Enantio- and Diastereoselective Synthesis of (Protected) 2-Formyl- and 2-(Hydroxymethyl)-1-phenylalkane-1,3-diols from Chiral 2-Methoxy-3-tosyl-1,3-oxazolidines by Subsequent Asymmetric Formylation and Aldolization

Abstract

Trimethylsilyl enol ethers are successively converted into chirally protected α-formyl ketones by asymmetric formylation with the 2-methoxy-1,3-oxazolidine 2, transformed into the corresponding, thermodynamically determined (Z)-TMS enol ethers, and then are allowed to condense with aldehydes. All steps proceed with high stereoselectivity. Some synthetic options, arising from the three differentiated oxygen functionalities in the intermediates 8 are illustrated for the title target compounds.