Organic Chemistry 1 Class Notes/Material for whole semester
Organic Chemistry 1 Class Notes/Material for whole semester Chem 341
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This 31 page Bundle was uploaded by Mary-elizabeth Notetaker on Wednesday May 4, 2016. The Bundle belongs to Chem 341 at University of Louisville taught by Dr. Burns in Fall 2015. Since its upload, it has received 19 views. For similar materials see Organic Chemistry 1 in Chemistry at University of Louisville.
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Date Created: 05/04/16
• Cation- missing e-(positive charge) • anion- more e- than neutral atom(negative charge) • neutral atom- # protons = # e- • matter- atoms...building blocks nucleus- made of p+ & neutrons ‣ electron cloud of e-'s • isotopes- 2 atoms of the same element w dif # of neutrons,so have dif mass # H vs.D dif reactivity C C • nmr- nuclear magnetic residence spectroscopy • rows(periods) & columns(groups) on PT elements in same row are similar size elements in same column have similar reactivity (electronic & chemical) ‣ Li,Na,K:want to be +1,counter cations..want to give up 1e- • ex) Li --> Li+ + e- ‣ Mg:can give up 2 e-...electropositive,wants to be 2+ ‣ gp 4 & on are more electronegative..want to be - • F --> F- • anions- neg charge and lone pair(2 e-) if has single e-,its a radical (odd # of e-..very reactive) in middle of table,elements form more covalent bonds(equal e- sharing) • s( ) & p( ) oribitals:1s,2s,2p,3s,3p,4s,3d,4p,5d P orbitals:ﬁgure 8 ‣ in valence in most atoms(further from nucleus)..lose e- ﬁrst ‣ higher E ‣ can have 3 types of orientations ‣ holds 6 e- S orbitals:spherical ‣ closer to nucleus ‣ lower e- ‣ holds 2 e- *ﬁll orbitals 2 at a time bs each go opp way* • ionic compounds:LiF,NaCl • covalent compounds:H2,NH3,CDCl2,CH4 not that much dif in electronegativity,easier to share e-...still get dipole moments(polarization) since C is more EN than H(this is what leads to reactivity) • Bond number: C has 8e- around it...4 valence e-...so can make 4 bonds # bonds an atom can form is 8- # valence e- ‣ ex) N has 5 valence e-,so 8-5= can form 3 bonds • O...8-6= 2 bonds • Lewis Stx 1) draw only valence e- 2) second row element(H,Li,Na excluded) want octect if possible 3) each H atom wants 2e- to make lewis dot stx ‣ 1) count valence e- ‣ 2) arrange the atoms (how you think they should go) ‣ 3) arrange the e-'s around the atoms ‣ 4) assign formal charge (make sure you account for lone pairs) heteroatom- atoms other than C or H (usually have lone pairs) • FC- determine number of e- around an atom and compare it to the valence e- the atom started with • FC= #valence e- - #e- an atom owns • FC= #valence e- - #unshared e- - # of bonds atom "owns" all unshared e- & 1/2 of shared e-s heterolytic cleavage- unequal sharing of e-..generates ions homolytic cleavage- equal sharing of e-...generates radicals exceptions to octet rule: ‣ 1) group 2 & 3- too few e- in neutral state ‣ 2)elements in 3rd row # and atom type dictate rx and reactivity • C2H6O...draw lewis stx • resonance- 2 lewis dot stx w/same placement of atoms(cant break single bonds,can break dbl or triple),but have diff e- arrangement..NOT isomers resonance hybrid- true stx of resonance atoms..shows true form resonance allows e- to be delocalization around 2 or more atoms(more stable when can delocalize..lower E resonance rules: ‣ 1) differ in number of multiple bonds & number lone pair e-'s ‣ 2) cant add/lose e-'s ‣ 3) must have valid lewis stx • determining molecular shape- det'd by bond lengths(BL) and bond angels(BA) bond length decreases across periodic table as size of atom decreases BL increases down a group as the atoms size increases • bond angle- determines shape arournd atom bonded to 2 other atoms # groups arond atom dets geometry of atom...group can be atom or lone pair e-'s most stable arrangements keeps groups as far away from each other as possible ‣ two-linear- 180 (two atoms around central atom) • single,double,or triple bond ‣ three- triginal planar- 120 (3 " " " ") • single or double bonds ‣ four- • tetrahedral(preferred)- 109.5 (4 " " " ) single bonds • square planar- 90 • 3D drawing ‣ solid wedge - front of plane ‣ dashed wedge- behind the plane ‣ straight line- bond in plane multiple ways to draw molecule as you move it around wedges/dashes used for groups that are really infront/behind each other sterics- has impact on 3D shape of a molecule ‣ (electronics- about bonding) ex) N containing compound w 3 groups(1 lone pair)- trigonal pyramid(107 ) ‣ lone pair takes up more space bc of lone pair e-'s and bonded e-'s • lone pair e-'s have more steric repulsion ex) H20- bent..two bonds and 2 lone pairs(105 ) • bonded atoms compressed into smaller space w smaller bond angle • drawing organic mols condensed stxs used for chains not rings (ex:CH (CH2) CH ) ‣ rules: • atoms drawn and bonds omitted • atoms placed next to atoms they neighbor • parentheses used around similar groups bonded to same atom • lone pairs of e-'s ommitted ( on heteroatoms) *methyl- ch3 *methine- CH *methylamine- ch2 ex) ex) drawing skeletal stxs- used for chains and rings ‣ rules: • assusme C at junction of any 2 lines or line end • assume enough H around each C to make them tetravalent • draw in heteroatoms(N,O,halogens..lone pairs) & H directly bonded to them *two lines come together implies 2 H *terminal line implies 3 H *three lines come together implies 1 H -mechanisms- show lone pairs...for products,dont have to show lone pairs(do) double bond:ex) triple bond:ex) • cautions for skeletal stxs: charge on c atoms takes place of 1 H atom charge det's # of lone pair e-s ‣ neg charge= c has 1 lone pair e-s ‣ pos charge= c has no lone pair e-'s • orbitals ad bonding- h atoms and dihydrogen simplest system- h2 ‣ two h atoms combine to form h2 by overlap of their 1s atomic orbitals(AOs) ‣ the e- density from theAO overlap is concentrated in a sigma bond between the two H atoms c- 2 core e-'s and 4 valence e-'s ‣ c wants 4 bonds but cant useAOs • use new orbitals called hybrid orbitals( little bit of both s & p) to form bonds...lower E hybridization- combo of 2 or moreAOs to form sae # hybrid orbitals w same shape and e ex) - four sp3 hybrid orbitals follow shape of tetrahedron( 4 groups) C has sp3 orbitals then H 1s orbital bonds to c's hybrid orbitals ‣ trig planar hybridization- 3 bonds to central atom...3 hybrid orbitals plus one unused pAO • ‣ linear- 2 bonds to central atom...3 and p determining hybridization ‣ count group number(atoms and nonbonded e;s) around atom ‣ number groups corresponds to numberAOs *halogens only useAOs bc lower e • bonding and shape of ethane condensed -> 2D -> 3D -free rotation about C-C sigma bond(single bond) can occur in ethane -if double C=C bond....each c is trig planar and and c is sp hybridized and 1 2p oribital left - acetylene- two groups around c • bond length & strength as # e- btwn 2 atoms increases,bond becomes shorter and stronger length and strength of c-h bonds ary depending on hybridization on c atom • sp hybrid= one 2s/2 hybrid= 50% s character • electronegativity- measure of an atoms attraction for e's in a bond dipole moments...use arrows to show dipole side(towards more EN atom) arrow shows polarity direction c-cl bond known as polar covalent bond(simple polar) net dipole use En values to ﬁnd polar bonds and dipole directoins det geometry around atom and decide if dipoles cancel(opp way) or reinforce(go same way) each other in 3D shape Chapter 2 • Bronsted: acid(A)- p+ donor • inorganic:HCL,H2SO4,HSO4- H2O,H3O+ • organic:CH3CO2H(acetic acid),citric acid ‣ all (H-A) bonds contain a proton ‣ net charge can be zero,+ or - base(B)- p+ acceptor • p+ is a atom w/out its e- (H+) ‣ inorganic: ‣ organic: (B) contain lone pair e- or are bonds net charge can be zero or - • normality- unit of reactivity....reactive L perV 1 M HCL= 1 normal • make sure to have the appropriate counter ion w charged bases • molecules can contain both acidic h atoms and lone pair e-s • bronsteed a/b rx transfer H+ froma to b 1 bond broken/1 bond formed e- pair of base forms bond w h+ of acid H-A loses p+ to make H-B,leaving e- pair in H-A bond onA • acid strength and pKa acid strength- tendency of an acid to give up a p+(H+) how do we measure acidity:using eq constants (Keq) Kew= P/R ‣ H2O is constant(rx done in sea of solvent) so above eq can be rearranged and Ka can be deﬁned as • Ka(acidity constant)= [H2O][Keq] • • how does Ka relate to acidity? stronger acid,further eq lies to P (right),so the larger the Ka ‣ most organic acids have small Ka(10^-5 to 10^-50) • pKa would be 5 to 50 ‣ most inorganic acids have larger Ka(10^0-10^10) • more acidic acid ‣ use pKa • pKa=-log(Ka) log is an exponent ex) log(10^-5)=-5 • memorize table 2.1 • inverse relationship btwnAcidity and basicity • strong acid readily donates H+,forms weak conj base • strong b readily accepts H+,forms weak conj base • log scaleL small pKa difference translates into large numerical diff • if rx is 5 pKa units diff or more,rx will def go..if less than 5 may or may not go, if less than 3 will not go relates to how hot a rx will be CH3NH2 and NH3 are similar -H and -CH have similar EN) so pKa of N-H bond in CH3NH2 is around 38(actual is 40) ‣ NH3 works for almost all amines ‣ H2O works for almost all alcohols ‣ carboxilic acids all about 5 ‣ MEMORIZE 2.1TABLE • stronger a rx w stronger b to form weaker a/b eq favors formation of weaker a/b • anything that stabalizes a conj b(A:) makes the corresponding a(H-A) more acidic factors det acid strength: ‣ resonance effects • delocalization=stability more atoms you can delocalize charge across..more resonance stxs you scan draw,the more stable it is=less reactive=weaker conj b deprotonate like to like (ex:sp3 to sp3) ex) methane v cyclopentadiene..carbanions not stable....cyclo can delocalize - charge about all c's...methane pka very high(50-least acidic),of cyclo low(15- much more acidic) ‣ element effects • across a row,acidity of H-A increases as EN ofA: increases,so pKa decreases • down a column..atom size inc and EN dec bigger halogen ions are the more stable they are ‣ ex) Br anion is much larger than F anion...Br anion is less EN than F,and therefore Br anion is more stable down a column,size(not EN) dets acidity ‣ positive or neg charge is stabalized when spread over larger v as you go down a group the acidity of H-A inc as size ofA: inc ‣ hybridization effects • lower pka = higher acidity= least # of hybrd orbitals used(most s character...more acidic...more stable)..closer to nucleus acidity of h-a(conj acid) inc as %s character ofA:-(conj b) inc ‣ inc s character = inc stability as s% inc • ex)ethane is 4 sp3 hybrid orbitals(20%s),ethylene is sp2 h orbital(33%s),acetylene is sp h orbital(50%s) • ‣ inductive effects- presence of EN atoms..only few bond diff(pull thru single bonded network of) • how stable is conj base? dont do well will 3 bonds away..only up to 2 • ethanol v triﬂuoroethanol...ethanol conj base is more stable than conj base in ethanol bc O in ethanol has neg charge and in triﬂ there are more charges pulling diff ways • aciity of H-A inc w presence of e- withdrawing groups inA:-(conj base) • more EN atom and closer to site of neg charge,greater inductive effect no matter what factor being discussed always use same procedure to compare acid strenth of any 2 H-A's(acids) ‣ always draw conj B ‣ det which conj b more stable ‣ more stable conj b=more acidic a • stable=unreactive • common a inorganic a:HCL,HNO3,H2SO4,etc....pKa<0(very acitic) organic a:CH3COOH[acetic a](pKa=4.8) ,TsOH[p-toluenesulfonic acid] (pKa=-7..inorganix acid that works like inorganic,and is a solid) ***no correlation btwn numb of resonance stxs and pKa*** bc also has to do w what atom - charge is residing on • common b inorganic:OH-(Na+),-OCH3(Na+) organic b:conj b has high pka(very basic..50) • lewis a/b lewis b- e- pair donor ‣ ex: ‣ all bronsted b are lewis b ‣ lewis b stx same as bronsted b,,,both have available e- pair(lonne pair e- or e- pair in pi bond) ‣ bronsted b always donats e- pair to p+,leweis b lewis aL e- pair acceptor( e- defﬁcient) ‣ all bronsted a are also Lewis acids • lewis a/b reactivity e- rich rx w e- poor e- from where they are to where they aint ‣ rx arrow from lone pair to where its going: electrophile- Lewis acid what if lewis a/b rx is formed and one bond broken? ‣ 3 things to do: Chapter 3 • what are the characteristic ft of an organic compound? organic mol ‣ have C-C and C-H sigma bonds...strong,nonpolar,hard to break ‣ heteroatoms- more EN..atoms other than C & H • common:NOSP & halogens • have lone pairs and create e- deﬁcient sites on C(EN) ‣ pi bonds..common:C=C and C=O • easily broken in chem rx,makes mol a base and nucleophile functional groups ‣ x- halogens(more EN than C)...creates dipole moment...can create dipole moment from C=C in double bond ‣ fx group behaves same way whether bound ot 2 or 20 Cs so we can abreviate C,H portion of a mol by "R" ‣ didiving up fx groups: • hydrocarbons- made of C & H ‣ aliphatic ‣ aromatic • earliest known aromatic compounds had strong odors • simplest:benzene • six membered ring w/3 pi bonds of benzene comprise a single FG conjugate 3 dbl bonds together(alternating)..releases odor phenyl group- C6H5 can draw resonance stxs, stable,not very reactive alkanes- C-C bonds and no fx group(FG) alkenes- C=C double bonds as FG ‣ bronsted base can react w/ a strong bronsted base and protonate it alkynes- C-C triple bonds as FG • compounds w/ a C-Z(Z is EN element) sigma bond- several FG contain these bonds ‣ EN heteroatom Z creates polar bond,making C e- deﬁcient alkyl halide:-x(halogen group) alcohol:-OH (hydroxyl)) ether:-OR (alkoxy group) amine:-NH2 (amino group) thiol:-SH (mercapto group) sulﬁde:-SR (alkythio group) • compounds w/ a C=O group...carbonyl group ‣ polar C-O bond makes carbonyl C e- deﬁcient(electrophile) ‣ lone pairs on O allow O to react as nucleophile/base ‣ carbonyl group contains pi bond that is easily broken aldehyde:C=O carbonyl ketone:C=O " carboxylic acid:-COOH ester:-COOR amide:-CONH2,-CONHR,-CONR2 acid chloride:-COCl ‣ importance of fx groups:det's properties in a mol • bonding and shape • type and strength of IM forces IM forces- intx that exist between mols IM forces also called noncovalent intx/nonbonded intx fx groups det type and strength ionic compounds:opp charges particles held together by extremely strong electrostatic intx ‣ much stronger than IM forces in covalent mols..hard to break up thru melting/boiling IM in covalent ‣ nature of forces btwn covalent mols depends on FG present ‣ 3 diff intx: • van der waals- all mols...London forces/dispersion weak intxs caused by momentary changes in e- density(brief temp dipole) w/SA...larger SA of mol...(spheres are weaker) ‣ larger attractive force btwn 2 of same mols ‣ stronger IM forces • polarization- imp when condifering van der waals measure of how the e- cloud around an atom responds to changes in electrical envir ‣ larger atoms have more looselt held valence e- and are more polarizable than smaller atoms w tightly held e-s dipole-dipole intx- attractive forces btwn permanent dipoles of 2 polar mols ‣ dipoles in adj mols align so that partial + and - in close proximity • H bonding- electrostatic intx btwn H atom of -SH,-OH,-NH, or HF and lone pair e- of O N or F atom in another mol H bonding is strongest of 3 types of IM forces • IM forces- summary...as polarity of a mol inc,so does strength of its IM ‣ physical props • BP- temp at which liquid mols are converted to gas....stronger IM forces=higher BP BP and IM forces- relative surface area and polarizability also affect bp ‣ for all compounds w/similar fx groups • larger SA=higher BP • more polarizable=higher BP • MP- temp at which solid is converted to liquid phase stronger IM forces= higher MP for compounds w similar fx groups,more symmetrical the compound,the higher the melting pt symm mols pack together well without groups hanging off in chains trends: ‣ for covalent mols of approc same mol weihgt,the mp depends on the ID of the fx group ‣ stronger IM attraction,higher MP(same for BP) ‣ inc IM forces = inc MP nomenclature chem reactivity • solubility- extend to which solute dissolves in solvent e needed to break intx btwn solute mols or ions comes from new intx between solute and solvent trends: ‣ like dissolves like • polar dissolves polar • nonpolar dissolves polar • nonpolar doesnt dissovle polar and vice versa • nonpolar of weakly polar compounds dissolve inL nonpolar solvents weakly polar solvents sol of organic mols: ‣ sol of organic mol in h2o det by # h bonding fx groups it has and the number of C present • 1 H bonding FG for 5 C= h2o sol • ex) butane solutble in CCl4 but not in h20(bc nonpolar)...acetone sol in both anything w carbonyl group is miscible in h20 of alc ‣ water sol of organic mols • size of organic mol w polar FG dets its water sol • low mol weight alc like ethanol is sol in water • cholesterol,with 27 C atoms and only i OH group,has c skeleton too large for oh group to solubilize by h bonding so it is insol in water from like C8 to C9...begins to become insol • hydrophobic- not water sol..greasy • hydrophilic- polar part of mol that can h bond to water • in cholesterol,hydroxyl group is hydrophobic • • strong b are also strong nucleophiles(e rich[-])...(electrophile e poor[+]) • know lew a/b and arrows • Forces perpendicular to a displacement do no work • One force does pos force on displacement,and one does neg • Work done by vector:Parallel component of force X mag of displacement • GW1: • Work done by constant force w= • pos work when:relative dir of F and r are in same direction • Neg work when:" " " " in opp dir • 0 work when:" " " perpendicular ‣ only when constant force,otherwise eq won't work ‣ Constant forces: • Fg....W= m & g are positive Is positive distance Positive work when obj moves down Neg wok when obj moves up 0 work when obj moves horizontally • Work done by spring...Not constant W = ‣ pos work when object moves towards eq ‣ Neg work when object moves away from eq ‣ 0 work " " did as much pos work as it did neg work- same distance from eq at beggining and end • Work- transfer of E..By: change total amt e by adding/subt E from system ‣ nonconservative(nc) Convert from one E form to another ‣ only when work done by special forces.. • conservative(c) gravitational spring pulled away from eq • ex1) M pulls on box w 210N at 30 deg above horiz.How much work doesT do on the box when moved 8.3 m across ﬂoor constant force,BC have value(210) Wt=(magT)( R)(cos ) • Ex2) L and M get C down(50kg) then 2 push box 8.5m across ﬂoor.M pulld on box got w force 210N at 30deg above horiz and fk=0.5,how much work Larry do?Avg force from L? Work E theory: K=Wnet KE:E from motion. KE=0 BC 0-0 work done by friction ‣ normal: GW2:15kg box at bottom of frictionless ramp.Pulled by cable to top,2.5x higher than bottom,and stops.How much w does each force on box do during lift? GW:0.5kg block dropped from h above spring w constant k=800N/m.Block compresses spring d=10cm before stop.What h above spring was block released from initially? HW ex:2.2kg mass pushed against hor s force 23N/cm on frictionless air table.Spring attached to tabletop,and m is not attached to s.S compressed enough to store 10.5J of Pe,then mass is released from rest. Greatest speed m reaches? How far s compressed to get that Pe?... pick 0 pt for gPe: Use +g when you have object high up(above 0)..Inc as go up if below 0 pt then use -g W/ work and change in Pe,ﬂip signs..,conservative force doing -W means stored Pe • Impulse- change in momentum (delta p) • CT1 must get rid of p going N by pushing S,to E by pushing E velocity and momentum always in same dir p=m Ex1) 200kg truck going 40m/s N turns E and accel to 50m/s.Net work? Mag and dir of delta p? Gw1) soccer ball(m=40) rolls hor L at 20m/s.Player kicks to giveV of 30m/s 30 deg above hor to R,mag and dir of delta p as it was kicked? Impulse( )- change in p...How force acts over time to change p For constant force:J=F t= P... avg force larger t becomes,the smaller the force becomes Ex2) same soccer ball still going same dir..If ball in contact w players foot for 0.010s,what is impulse of avg force on ball as kicked? Change in p,impulse,and avg force all point in same dir Ex3) small car m=1000kg going N towards intx at 15m/s.Truck m=2000kg going E at 10m/s on cross st approaching Same intx.Mag and dir of total momentum of truck/car system? . • alkyl halides- organic mols containing halogen atom bonded to sp3 hybridized atom clasiﬁed as primary,secondary,or tertiary depending on iodide- primary bromide- secondary tert chloride- • types: vinyl halides- have halogen atom(x) bonded to c=c (dbl bond) (sp2) aryl halides- halogen atom bonded to benzene ring(sp2) allylic halides- x bonded to c atom adj to c=c dbl bond(sp3) benzylic halides- have xbonded to c atom adj to benzene ring(sp3) • naming alkyl halides ﬁnd parent C chain containing halogen ‣ name chain as alkane,with halogen as sub bonded to longest chain ‣ number the chain...begin at end nearest ﬁrst sub, either alkyl or halogen ‣ name and number sbs ‣ alphabetize • MIRANDA NOTES • bond breaking in nucleophile(lone pair,neg charge or neutral) sub mechs order of bond breaking making? ‣ 3 posibilties: • bond making/breaking at same time mech is one step bimolecular rx,rate depends on concentration of both reactants rate eq is second order • bond breaking ﬁrst mech has 2 steps and carbocation is formed as intermediate ﬁrst step is rate det...rate depends on concentration of RX only rate is ﬁrst order • bond making ﬁrst mech has inherent prob..violates octet rule bc intermediate generated in ﬁrst step has 10 e- around c bc 2 other mech poss do not violate fundamental rule,last poss can be disregarded ***F too EN to undergo sub • kinetics and mechs kinetic data show rate of rx 1 depends on concentration of both rxs,which suggests a bimolecular rx w one-step mech ‣ ex) of Sn2(sub nucleophillic bimolecular) mech • curved arrow notation used to show e ﬂow • make halide ion • transition state:always has partial bonds to nucleophile and leaving group can be partial charges on the nucleophile and or leaivng group inversion:bond of nucleophile in product always on oppside relatve to bond of leaving group in starting mat..."backside attack"(s to r or vice versa) ‣ results in inversion of conﬁg at stereogenic center sub reactivity ‣ as number of R groups on c w/in the leaving group increases,the rate decreases ‣ methyl and primary alkylhalides undergo sn2 rx easily ‣ secondary reacts more slowly ‣ 3 do not undergo them bc of steric effects ‣ bulky r groups near rx site make steric effects:electrostatic potential maps illistrate effects of steric hindrance around c bearing the leacing group in a series of alkls ‣ effects:inc number r groups on c win leaving group inc crowding in transition state and dec rx rate ‣ sn2 fastest w unhindered halides • faster;less crowded,lower e • slower;more crowded,higher in e characteristics slide kinetic data show the rate of rx 2 depends on concentration of only the alkylhalide ‣ suggests 2 step mech in which rate det step involves alkylhalide only ‣ ex) Sn1(sub nucleophilic unimolecular) mech • racemizaiotions: 1st step:generates sp2 Carbocation that is achiral bc trig planar 2nd step:attack of nuc can occur on either side to afford 2 prods ‣ no preference..so racemix mix(equal amt of 2 enantiomers) formed...process called racemization • with h20(neutral nuc) the initial prod of nuc sub loses proton to form the ﬁnal neut product sub rx:affected by type of alkylhalide incolced ‣ as num of r groups on c w leaving group inc,rate ince • 3 go rapidly • 2 go slow • methyl and 1 halides do not go ‣ trend is opp of sn2 carbocation stability- effect of type alkyl on sn1 rx explained by carbocation stability ‣ carbocations class as primary,2,or 3 based on num r groups bonded to charged c atom ‣ as r group inc,carbocation stability inc ‣ inductive effect:pull e- density thru sigma bond networ(from EN diff btwn atoms) • inc numb of e- donating r goups inc carbocation stability • more stability from inductive..thru bond ‣ hyperconj- thru 3D space CH 9 PP additions: • slide 1: alc chem dictated by ability to H bond tertiary alcs less useful,primary and secondary can elim water • slide 2: phenol- aromatic alc enol- vinyl alc..less stable form of ketones alcs bound to sp3 c is focus rn ether- inert,good solvs(symm) • slide 3: unstable 3 member ring..very rx from ring size and angle strain • slide 5:linear alcs IUPAC+longest chain(instead of "ane",sufﬁx will be "anol",so remove "e" and add "anol")+ number location of alcohol and subs(alc gets lowest # possible)(other subs get higher)+ name and number subs to create ﬁnal name • slide 6:cyclic alcs alc is c1 but dont have to number it that c bc assumed..number other subs • slide 7: know common names ‣ isopropyl,glycerol,ethylene glycol • slide 9 and 10: simple: ‣ ether=diethyl ether ‣ name subs on each side of O complex: ‣ call it the alcoxy • slide 12: 3 memb ring is oxirane...add subs to beginning of naming..dont use epoxide 1,2,3 ring.o gets c1 and dsnt have to be named • slide 13: alkene oxide instead of epoxides ethylene= ethylene oxide(oxirane name) • slide 16: dipole is towards O so gets delta -,H gets delta + smaller alc=easier h bond break up h bonding with bulky alc • red of org mols 3 types of red's diff in how h2 added simplest reducing agent is h2...red w h2 are carried out w metal catalyst • hydride red add hydride(H-) and a proton(H+) most common hydride red agent has H atom bonded to B orAl simple examplesL sodium borohydride(NaBH4) and lithium aluminum hydride (LiAlH4) ‣ both deliver H- to substrate and proton is added to h2o or alc • catalytic hydrogenation addition of h2 in presene of metal catalyst only catalyst consists of metal(Pd,Pt,Ni) absorbed onto a ﬁnely divided inert solid(ex:charcol) H2 adds in syn fashion.. ‣ cyclic alkene w syn...always cis product ‣ h gas reacts w metal surface ("docks")...adds from metal face rate of hydrogenation- STERICS rapid sequential add of h2 occurs from side of alkene complexed to metal surface= syn less crowded dbl bond complex more readily to catalyst surface= faster rx 3 ways h2 can add to triple bond ‣ 2 eq h2 to to get alkene ‣ 1 eq h2 in syn fashion to get syn alkene • hydrogeation of alkenes using lindlars catalyst hydrogenation to cis alkene is stereoselective rx,bc only one sterioisomer formed alkene to alkane,cant stop it alkyne to alkane,can stop w lindlars catalyst • red and ring opening of polar c-x sigma bond w LiAlH4 alkyl halides can be reduced to alkanes w LiAlH4 epoxide rings can be opened w it to form alcohols • mechanusm of li w alkyl sn2...unhindered ch3x and priary alkyl are easily reduced than secondary and tert in nunsymm,nuc attackof h+ at less sub c • ox chem- peroxide ox agents ‣ reagents w o-o bond ‣ reagents w metal-o bond ox agents w o-o:o2,o3(ozone),h2o2(peroxide),(ch3)cooh( tert-but hydroperoxide) and peroxyacids(RCO3H) • ox agents w metal o bonds most common ox agents w metal-o bonds contain chromium 6+ or manganese 7+ common Cr6+ reagents include CrO3 and sodium or potassium dichromate(Na2Cr2O7 and K2Cr2O7) pyridinium chlorochromate(PCC) is more selective most common Mn&+ reagent is KMnO4 (potassium permanganate) other ox agents w metals include OsO4(osmium tetroxide) and Ag2O(silver(1) oxide) • epoxidation- add of single o atom to alkene to form epoxide..uses peroxyacid • peroxyacid alkene epox mech syn add of o atoms to either side of planar dbl bond • alkene dihydroxylation- addition of 2 hydroxy groups to dbl bond,forming 1,2- diol or glycol depending on reagent,2 new OH groups can be added to opp sides • anti dihydroxylation epoxidation followed by ring opening w -OH or H3o+ • syn dihyd when alkene is treated w KMnO4 or OsO4 • ozonolysis:oxidative cleavage of alkenes breaks both sigma and pi bonds of dbl bond to form 2 carbonyl compounds cleavage w ozone(o3) forms ketone and aldehyde if tri/di sub'd mech: ‣ addition of o3 to pi bond of alkene forms unstable int called molozonide, which reagrranges to ozonide in stepwise process ‣ unstable ozonide is red to afford carbonyl compounds • ZN in h2o or dumethylsulﬁde(ch3sch3) are 2 common reagents used to convert ozonide into carbonyl compounsd • oxidative leavage of alkynes undergo ox cleavage of sigma or pi bonds of trip bonds internal alkynes are oc to carboxycilic acids (rcooh) terminal--> carboxylic acid and co2 from sp hybridized c-o • ox of alc primary- ox to aldehydes(c=o w alkyl group on one side and h on other) or carboxylic acids by replacing either one or 2 c-h bonds by c-o bonds ‣ ox to aldehyde(rcho) under mild conditions with pcc in ch2cl2 ‣ ox to carboxylic acid(rcooh) under harsher rx conds(na2cr2o7, k2,cr2,o7,or cro3 in presence of h2o or h2so4) secondary- ox to ketones by replacing one c-h bonds by c-o tertiary- no h atoms on c w oh group,so hard to ox..no rx • chromium ox reagents ox of alcs to carboyl is carried out with Cr6+ oxidants,which are red to cr3+ cro3,na2cr2o7,and k2cr2o are strong,nonselective ox used in aq acid (h2so4 + h2o) pcc is soluble in ch2cl2(dichloromethane) and can be used w/out strongA, so more selective •
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