Prochiral diester malonates

There are also recent reports of the lipase-catalyzed enantioselective hydrolysis of prochiral diacid derivatives such as 2-substituted malonates, barbiturates, and highly substituted, sterically hindered 1,4-dihydropyridine derivatives using acy-loxymethyl groups to enhance the reaction rate. An example of a prochiral diester hydrolysis is illustrated in eq 10. ... 

Enantioselective enzymatic ester hydrolyses of prochiral trimethylsilyl-substituted diesters of the malonate type have been applied for the synthesis of the related optically active monoesters68. As an example of this particular type of biotransformation, the enantioselective conversion of the diester 82 is illustrated in Scheme 17. Hydrolysis of compound 82 in phosphate buffer, catalyzed by porcine liver esterase (PLE E.C. 3.1.1.1) or horse liver acetonic powder (HLAP), gave the optically active monoester 83 (absolute configuration not reported) in 86% and 49% yield, respectively. The enantiomeric purities... 

A limited number of acyclic and cyclic prochiral dicarboxylic acid diesters were found to be good substrates for hydrolysis catalyzed by lipases (Table 11.1-12). Notable examples which give a good illustration of the potential of hydrolases as well as of the trial and error approach one relies on to a certain extent are the dithio acetal derivative 9 and the fluoro alkyl malonates 1-8. The dithio monoester 9 is obtained with different lipases with high enantioselectivities and yields despite its remote chiral center. Candida cylindracea lipase is the enzyme of choice for the synthesis of fluoro alkyl malonates with small alkyl groups. An astonishing observation was... 

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