Reactions of the cross-conjugated dienolate of 3-substituted 2-cyclohexenone 1b and 1c, 2-cyclohexenone (1d), and 2,3-disubstituted 2-cyclohexenone 1e with methyl (S)-3-(2,2-dimethyl-1,3-dioxolan-4-yl)-2-propenate (Z)-2 gave highly diastereoselectively 3b, 3c, 3d and 3e, respectively. The presence of a methyl group at C-6 on cyclohexenone ring caused the stereoselectivity to change completely, so that