Major products A and B formed in the following reaction sequence, are [figure]
- [figure]
- [figure]
- [figure]
- [figure]
Answer
(1) [figure]
Solution
PBr3 replaces the -OH group by -Br on the same carbon, so A is 1-bromo-2-methylcyclohexane.
Alcoholic KOH on heating causes dehydrohalogenation ( -elimination). By Saytzeff rule the more substituted alkene is the major product: H is removed from the -carbon carrying CH3.
B is 1-methylcyclohexene (double bond between the ring carbon bearing CH3 and the carbon that carried Br).
Answer: (1)