Which compound is optically active ?

Options

A. 2-methylpropan-1-amine
B. Butan-2-amine
C. Butan-1-amine
D. 2-methylpropan-2-amine

Answer

B

Explanation

The compound with one chiral carbon atom is optically active.
(A) 2-methylpropan-1-amine : `H_(3)C-overset(CH_(3))overset("| ")underset("H ")underset("| ")("C ")-overset("H")overset("|")underset("H")underset("|")("C")-NH_(2)` has no chiral carbon.
(B) Butan-2-amine : `H_(3)C-overset("H ")overset("| ")underset(NH_(2))underset("| ")("C"^(**))-CH_(2)CH_(3)`
The asterik marked carbon is a chiral carbon.
(C ) Butan-1-amine : `CH_(3)-CH_(2)-CH_(2)-CH_(2)NH_(2)` has no chiral carbon.
(D) 2-methylpropan-2-amine : `CH_(3)-overset(CH_(3))overset("| ")underset(NH_(2))underset("| ")("C ")-CH_(3)` has no chiral carbon.