1. Predict the elimination products of the following reactions. When two alkenes are possible, predict which one will be the major product. Explain your answers, showing the degree of substitution of each double bond in the products.
2. Which of these reactions are likely to produce both elimination and substitutionproducts?
(a) 2-bromopentane + NaOCH3
(b) 3-bromo-3-methylpentane + NaOMe (Me = methyl, CH3)
(c) 2-bromo-3-ethylpentane + NaOH
(d) cis-1-bromo-2-methylcyclohexane + NaOEt (Et = ethyl, CH2CH3)
Step 1 </p>
(a) 2-Bromopentane is a secondary alkyl halide. It is reacted with sodium methoxide to form two elimination products and one substitution product. In general, secondary alkyl halides are participated in reactions.
The degree of substitution in pent-1-ene is 1 and pent-2-ene is 2.
Step 2 </p>
(b) 3-Bromo-3-methylpentene is a tertiary alkyl halide. It is reacted with sodium methoxide to form only two elimination products. In this reaction, no substitution products are formed. In general, tertiary alkyl halides are not participated in reactions due to steric hindrance.
The degree of substitution in 3-methylpent-2-ene is 3 and 3-methylenepentane is 2.