The number of optically active compounds from the following is . [figure] CH3-CH2-CH2-CH2-OH, CH3-CH2- Cl |CH-CH3, CH3-CH2-CH2-CH2-Cl, (CH3)2CH-CH2-CH2-Cl
Answer
1
Solution
[figure]
(i): two identical chiral C with a plane of symmetry (dashed), so it is meso and optically inactive.
(ii): heptane-3,4,5-triol drawn symmetrical about C-4 (plane through C-4), so it is optically inactive.
CH3CH2CH2CH2OH and CH3CH2CH2CH2Cl have no chiral C, so they are inactive.
(CH3)2CH-CH2-CH2-Cl: C-3 carries two CH3 groups, so there is no chiral C; inactive.
CH3-CH2- CHCl-CH3: C-2 has four different groups (H, Cl, CH3, C2H5), so it is optically active.
Hence only 1 compound is optically active.
Answer: 1