MHTCET 15 May 2024 Shift 1 Paper

Concept:A chiral carbon atom is one that is bonded to four different groups.Explanation:The structure of 2-chloro-3,4-dimethylhexane is written as:$$\mathrm{CH_3-CH(Cl)-CH(CH_3)-CH(CH_3)-CH_2-CH_3}$$The parent chain has six carbon atoms numbered from 1 to 6.At C2: The attached groups are $\mathrm{CH_3}$, $\mathrm{Cl}$, $\mathrm{H}$, and the C3-group.All four groups are different, so C2 is chiral.At C3: The attached groups are $\mathrm{CH_3}$, $\mathrm{H}$, the C2-group, and the C4-group.The C2-group differs from the C4-group, so C3 is chiral.At C4: The attached groups are $\mathrm{CH_3}$, $\mathrm{H}$, the C3-group, and the C5-group.These four groups are different, so C4 is also chiral.At C5: It is attached to two identical hydrogen atoms, so it is not chiral.C1 and C6 are terminal carbons and therefore achiral.Thus, the molecule contains exactly three chiral carbon atoms.Answer:Three (Option C).