Abstract
Reaction of formaldehyde and trimethylaluminum with an enol ether derived from an aldehyde gives the adduct resulting from addition of hydroxymethyl and methyl groups to the enol ether double bond. The threo isomer is formed selectively (90-95%) from either isomer of the starting enol ether. The mechanism of this reaction is discussed. Reaction of formaldehyde and trimethylaluminum with an enol ether derived from a ketone gives the ene adduct, which should allow selective sequential reaction at the a and a' positions of ketones.