Creation of novel chiral synthons with enzymes: application to enantioselective synthesis of antibiotics.

Retrosynthesis was carried out to generate, from a target molecule, a symmetric diester in the prochiral or meso form. The symmetric diester was subjected to asymmetric hydrolysis with pig liver esterase to create the corresponding chiral half-ester. The chiral half-ester was converted into the target molecule by organic synthesis. Thus, various types of carbapenem antibiotics, negamycin, showdomycin, 6-azapseudouridine, cordycepin, aristeromycin, neplanocin A, and precursors of fortimicin were efficiently synthesized with the desired absolute configuration. The methods for asymmetric synthesis starting from substrates with sigma-symmetry have been extensively developed.