lution (0" C) of 1.45 g (10 mmol) of Me3SiDEA in dry EbO (2 mL) under nitrogen atmosphere and with magnetic stirring was added a solution of 0.97 g (10" 01) of 2a dropwise. The reaction mixture was allowed to warm to room temperature, and the conversion was judged, by'H NMR and GC analyses, to be complete after 12 h. Evaporation of the crude reaction mixture followed by vacuum distillation afforded la: 1.18 g (70% yield); bp 64-65" C (7.5 ...