Chapter 23, Problem 23.54P

Clopidogrel is the generic name for Plavix, a drug used to prevent the formation of blood clots in patients that

have a history of heart attacks or strokes. A single enantiomer of clopidogrel can be prepared in three steps

from the chiral $\text{α}-$ hydroxy acid $A$. Identify $B$ and $C$ in the following reaction sequence, and designate the

configuration of the enantiomer formed by this route as $R\text{ or }S$