Esterase-mediated synthesis of optically active GABA analogues containing a stereogenic all-carbon quaternary carbon atom

Esterase from Horse Liver (HLAP) was able to hydrolyze a series of linear and cyclic beta,beta-dialkyl-gamma-nitroesters, in spite of the well-known reluctance of hydrolytic enzymes to recognize and transform hindered substrates, such as those possessing a stereogenic quaternary carbon atom next to the reaction site. The resulting optically active gamma-nitroesters gave access to optically active beta,beta-disubstituted gamma-aminoacids as well as alpha,alpha-disubstituted succinic acids, both being biologically relevant compounds. (C) 2010 Elsevier Ltd. All rights reserved.