Practical Syntheses of (<i>S</i>)‐4‐Hydroxytetrahydrofuran‐2‐one, (<i>S</i>)‐3‐Hydroxytetrahydrofuran and Their (<i>R</i>)‐Enantiomers

Abstract

Abstract Optically active 4‐hydroxytetrahydrofuran‐2‐one ( 3 ) has been synthesized in good yield from optically active ethyl 4‐chloro‐3‐hydroxybutanoate ( 2 ) by refluxing with dilute hydrochloric acid. In a similar manner, optically active 3‐hydroxytetrahydrofuran ( 5 ) was prepared from optically active 4‐chloro‐1,3‐butanediol ( 4 ), which was derived from 2 by NaBH 4 reduction. These new cyclizations proceed without racemization.