$' A ^{\prime} \stackrel{ HNO _3}{\longrightarrow} X ^{\prime} \stackrel{ NaBH _4}{\longrightarrow} \underset{\text { Chiral compound }}{\text { } B ^{}}$
$\mathop C\limits_{\mathop |\limits_{COOH} } {H_2}\, - \,\,\mathop {\mathop C\limits^{\mathop |\limits^{OH} } }\limits_{\mathop |\limits_{COOH} } \,\, - \,\,C{H_2}\,\, - \,\,\mathop C\limits_{\mathop {||}\limits_O } \,\, - \,\,OH$