Mimicking aldolases through organocatalysis:: syn-selective aldol reactions with protected dihydroxyacetone

A practical organocatalytic strategy designed to mimic the L-rhamnulose 1-phosphate and D-fructose 1,6-diphosphate aldolases has been developed and shown to be effective in the preparation of carbohydrates and polyol derivatives. Threonine-based catalysts facilitated the aldol reaction of protected dihydroxyacetone or protected hydroxacetone with a variety of aldehydes to provide syn-aldol products with good yields and ee's up to 98%.