Optimized double kinetic resolution for the preparation of (S)-solketal

Article abstract of DOI:10.1016/S0957-4166(97)00057-8

The lipase AK (lipase from Pseudomonas sp.)-catalysed alcoholysis of racemic solketal (2,2-dimethyl-1,3-dioxolane-4-methanol) esters and acylation of solketal in organic solvents proceeded with E = 20-25. This enabled the preparation of the more reactive (S)-enantiomer with more than 30% total isolated yield (based on the racemate) and 95% ee by a double kinetic resolution strategy consisting of enzymatic acylation-chemical saponification-enzymatic acylation or enzymatic alcoholysis-enzymatic acylation sequences. Numerical calculations and theoretical plots for the optimal termination conversions for the 1st and 2nd resolution steps as well as for the find yields as the function of E is considered.