Diphenylprolinol silyl ether as a catalyst in an asymmetric, catalytic, and direct michael reaction of nitroethanol with alpha,beta-unsaturated aldehydes.

Diphenylprolinol silyl ether was found to be an effective organocatalyst in the enantioselective and direct Michael reaction of nitroethanol and alpha,beta-unsaturated aldehydes, affording the 1-hydroxy-trans-3,4-disubstituted tetrahydropyrans after isomerization. The generated Michael addition products are useful synthetic intermediates, which can be converted into chiral tetrahydropyran with a quaternary stereocenter, 3-substituted cis- and trans-prolines, and alpha-amino acid derivatives.