Kinetic resolution of a dihydrobenzofuran-type neolignan by lipase-catalysed acetylation

Abstract The kinetic resolution of 3,5′-dimethoxy-4′,7-epoxy-8,3′-neolignane-4,9,9′-triol 1 by lipase-catalysed acetylation in an organic solvent was investigated. Ten different lipases were screened for enantioselectivity in the reaction. The enantiomeric excess (e.e.) of the products was strongly dependent on the type of lipase used. After optimisation of the reaction conditions for Candida cylindracea lipase, the e.e. and yield of the reaction was improved greatly and, in some cases, the enantiomerically pure starting material 1 could be isolated, albeit in a low yield, with the acetylation affording predominantly (2 R ,3 S )- 1 and the (2 S ,3 R )-esters.