We have seen that an E2 reaction generally proceeds from a

Chapter 8, Problem 8.92

(choose chapter or problem)

We have seen that an E2 reaction generally proceeds from a conformation in which the b proton is anti-periplanar to the leaving group. A similar geometric requirement is also observed for other types of reactions such as the one below (J. Am. Chem. Soc. 2010, 132, 25302531). Under acidic conditions, compound 1 rearranges to form mechanistic intermediate 2, which then undergoes three additional mechanistic steps (along with the loss of an N2 leaving group) to give product 3. The conversion of 1 S 2 is beyond the scope of our current discussion. Draw a mechanism for the final three steps, as described: (x) The alkyl group anti-periplanar to the N+ 2 group undergoes a 1,2-shift to allow a backside displacement of N2. (y) The alcohol oxygen attacks the resulting carbocation. (z) The resulting oxonium ion is deprotonated. N N N O R HO R O O R R N3 Several mechanistic steps x y z 1 2 3 !