Diols monodichloroacetates

In another context, Cao and Qu showed that an enantioselective acylation catalysed by a chiral thioamide modified 1-methylhistidine methyl ester (Scheme 2.19) in combination with a DABCO-mediated racemisation of the substrate led to the efficient dynamic kinetic resolution (DKR) of meso-1,2-diol monodichloroacetates. As shown in Scheme 2.19, both cyclic and acyclic meso-l,2-diol monodichloroacetates could be transformed to the corresponding enantiomerically enriched (15, 2R)-heterosubstituted diol esters in good yields and moderate enantioselectivities of up to 74% ee. 

Scheme 2.19 DKR of meso-l,2-diol monodichloroacetates catatysed by a chiral thioamide and DABCO.

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