Useful Chiral Building Block

(R)-3-(Acetylthio)isobutyryl Chloride (1) was introduced into prolines followed by deacetylation to give Captopril. Captopril is an effective inhibitor of the angiotensin converting enzyme (ACE), which is utilized in the treatments of hypertension. Recently, there have been many other studies where 1 has been introduced into amino acids and nitrogen-containing heterocycles to make new products with improved medicinal effects.