Biotransformation of benzaldehyde toL-phenylacetylcarbinol (L-PAC) byTorulaspora delbrueckii and conversion to ephedrine by microwave radiation

In a 5 dm3 stirred tank reactor, bioconversion of 30 g benzaldehyde by cells of Torulaspora delbrueckii yielded 22.9 g of pure L-phenylacetylcarbinol (L-PAC). Facile functional group transformation of 4.5 g of L-PAC to 2-(methylimino)-1-phenyl-1-propanol by exposure to microwave irradiation for 9 min resulted in 2.48 g of product. Conversion of 4.8 g of 2-(methylimino)-1-phenyl-1-propanol to 3.11 g of ephedrine was achieved by exposure to microwaves in a reaction time of 10 min. The identity of all the products was confirmed by 1H NMR and FT-IR analysis. © 2002 Society of Chemical Industry