Question

An optically active alcohol A$\left(C_6{H}_{10}O\right)$ absorbs two moles of hydrogen per mole of A upon catalytic hydrogenation and gives a product B.The compound B is resistant to oxidation by $Cr{O}_3$ and does not show any optical activity.Deduce the structures of A and B.

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

(i) Since B is resistant to oxidation, it must be tert.alcohol.
(ii) Since B is optically inactive, it must have atleast two similar alkyl groups.
Thus the five carbon atoms can be adjusted into three alkyl groups(of which two are similar)either as
$-C{H}_3,-C{H}_3$ and $C_3{H}_7$ or as $C_2{H}_5,-C_2{H}_5$ and $-C{H}_3$.Thus the possible structure of alcohol B is either

Hence the corresponding compound A is either

However compound A is optically active so its structure should be
which contains a chiral C-atom.
$\therefore$