Regio- and enantioselective bioreduction of methyleneketoesters using both polymeric resin and cellulose matrix

Methyleneketoesters were prepared in >90% yield by performing an IBX oxidation of Morita–Baylis–Hillman adducts. A methodology was developed to achieve methyl 3-aryl-3-keto-2-methylenepropanoate reduction using a screening of yeast strains in three different reaction procedures to obtain products with both high yield and diastereoselectivity. The reactions conducted in water provided inferior yields (50%) for substrates 2b–c. Employing Amberlite® XAD7HP which was a substrate reservoir that also immediately extracted the products from the reaction medium after their formation, syn-4a–c and anti-4a–c were isolated in 60–70% yield, with high stereoselectivity (98–99% ee). The best results were obtained using substrates adsorbed on filter paper which provided products yields above 70%, a 99% ee and a diastereomoeric ratio (syn-4: anti-4) 9:1. Cellulose matrix has excellent potential to be successfully employed in general biocatalytic reactions.