Scalable Lipase-Catalyzed Synthesis of (R)‑4-(Acyloxy)pentanoic Acids from Racemic γ‑Valerolactone

Conversion of biobased platform chemicals to enantiopure compounds has become topical. We report a straightforward synthesis of 4-(acyloxy)-pentanoic acids from γ-valerolactone (GVL). An alkaline hydrolysis of GVL is followed by a stereoselective lipase-catalyzed acylation of the sodium salt. Acidic hydrolysis of the acylation product affords (R)-4-(acyloxy)­pentanoic acid and relactonized (S)-GVL. (R)-4-(Propionyloxy)­pentanoic acid and (R)-GVL are obtained with e.r. > 99/1. An additional enzymatic step following a slightly modified process affords (S)-4-(acetyloxy)­pentanoic acid with e.r. > 99/1. Simple access to enantiopure 4-(acyloxy)­pentanoic acids will stimulate the development of their novel applications, including biobased isotactic polymers.