Stereoselective Synthesis of Enantiopure Oxetanes, a Carbohydrate Mimic, an ϵ‐Lactone, and Cyclitols from Biocatalytically Derived β‐Hydroxy Esters as Chiral Precursors

Biocatalytically derived enantiopure alpha-substituted beta-hydroxy esters serve as excellent chirons for the synthesis of a diverse set of structures such as oxetanes, a carbohydrate mimic, an e-lactone, and carbocyclic and aromatic cyclitols. The starting materials can be easily accessed in enantiopure form from a-substituted beta-keto esters by biocatalytic reduction with Klebsiella pneumoniae (NBRC 3319). Ring-closing metathesis (RCM) is one of the key transformations used to create the carbocyclic/heterocyclic frameworks reported in this article. The synthesized cyclitols were screened for their inhibitory effect on a-and beta-glucosidases.