J. Uenishi et al., HIGHLY STEREOSELECTIVE ALKYLATION AT NEOPENTYL POSITION ON BETA,BETA-DIALKYL SUBSTITUTED GAMMA-BUTYROLACTONE RING, Tetrahedron letters, 36(33), 1995, pp. 5909-5912
The alpha-alkylation of t-butyldiphenylsilyl)oxymethyl-gamma-butyrolac
tone enolates by alkyl trifluoromethanesulfonate or dimethyl sulfate g
ives consecutive quaternary and tertiary, or two quaternary carbon cen
ters with high diastereoselectivities.