Q.Write structure of optically active alcohol having molecular formula C4H10O

Step 1. Recall the requirement for optical activity. A molecule is optically active if it contains at least one chiral centre -- a carbon bonded to four DIFFERENT groups -- and is not itself superimposable on its mirror image.

Step 2. Check each C4H10O alcohol isomer. n-Butanol (CH3-CH2-CH2-CH2-OH): its C1 (bearing OH) is bonded to H, H, OH and CH2CH2CH3 -- two identical H's, not chiral. Isobutyl alcohol ((CH3)2CH-CH2-OH): its C1 is bonded to H, H, OH, CH(CH3)2 -- again two identical H's, not chiral; its C2 is bonded to two identical CH3 groups, also not chiral. tert-Butyl alcohol ((CH3)3C-OH): its central carbon bears three identical CH3 groups, not chiral. Butan-2-ol (CH3-CH2-CH(OH)-CH3): its C2 (bearing OH) is bonded to FOUR different groups -- H, OH, CH3 (going one way) and CH2CH3 (going the other way) -- making i …

Checking each C4H10O alcohol constitutional isomer for a carbon bonded to four different groups (the structural …

• Proposing tert-butyl alcohol or n-butanol, overlooking that both have a carbon bearing two or more IDENTICAL substituents (ruling out chirality) at every position. …