Study on asymmetric hydrogenation of γ-keto acid catalyzed by Ni/Zn

Chiral γ-valerolactone is an important structural motif of many important natural products and bioactive molecules. This paper reports a cheap and efficient method to prepare chiral lactones. A series of chiral lactone derivatives were obtained by asymmetric hydrogenation of commercially available γ-aryl keto acids with hydrogen as hydrogen source with the Ni-Zn co-catalytic system. The catalytic system has shown good substrate applicability, affords corresponding chiral γ-valerolactones in up to 99% yield with up to 98% ee. The present methodology has provided an efficient and economical method for valuable chiral γ-valerolactones, and has important potential applications in organic synthesis and pharmaceutical industry.