Question

Draw the mechanism and use words to explain the following reactions:

The dehydration reaction of 2,2-dimethyl-1-cyclohexanol produces as the major product 1,2-dimethyl-1-cyclohexene

Answer 1

2,2-dimethyl-1-cyclohexanol protonation with H3PO4 or H2SO4 to give protonated product followed dehydration to give secondary carbocation then 2° carbocation undergoes a methyl shift to form a more stable 3° carbocation, which loses a proton to form 1,2-dimethyl-1-cyclohexene as the major product

AC CH, он CH3 heating major mechanism minor н.с сн н.с сн он ot CH protonation dehydration secondary ethvl shift carbocation CH3 CH3 loses a proton tertiary carbocation