COMPARED STEREOSELECTIVITIES OF THE ALKYL ATION AND ALDOLIZATION OF GAMMA-VALEROLACTONE ENOLATES

Alkyl condensation of enolates derived from the monosubstituted lacton es 1 and 2 is highly stereocontrolled and leads to the 2,5-trans struc tures. The use of carbonylated compounds as electrophilic agents leads to a complex mixture of the different theoretically possible stereois omers. The difference between the transition states of alkylation and aldol condensation, as evidenced by conformational analysis of the com pounds described here, sheds light on this result.