... shift of the C-7 methyl doublet (6 0.93) due to the anisotropy of the C - w - 1 0 ... was added dropwise to the cooled solution by syringe, and the reaction was stirred for 1 h at -78OC. The a,P-unsaturated aldehyde was dis- tilled from Na2S0, under Ar, and was added neat (1.5 mmol ...