Efficient Enzymatic Routes for the Synthesis of New Eight-membered Cyclic β-Amino Acid and β-Lactam Enantiomers.

Efficient enzymatic resolutions are reported for the preparation of new eight-membered ring-fused enantiomeric β-amino acids [(1,2)- and (1,2)-] and β-lactams [(1,8)-, (1,8)- (1,8)- and (1,8)-], through asymmetric acylation of (±)- ( > 100) or enantioselective hydrolysis ( > 200) of the corresponding inactivated (±)- or activated (±)- β-lactams, catalyzed by PSIM or CAL-B in an organic solvent. CAL-B-catalyzed ring cleavage of (±)- ( > 200) resulted in the unreacted (1,8)-, potential intermediate for the synthesis of enantiomeric anatoxin-. The best strategies, in view of , reaction rate and product yields, which underline the importance of substrate engineering, are highlighted.