Enamines, prepared readily from various carbonyl compounds, react with acetals or trialkyl orthoformates in the presence of Lewis acids such as BF3·OEt2 to give corresponding β-alkoxy carbonyl compounds or α-dialkoxymethyl carbonyl compounds in good yields. The reaction of dienamines with acetals or trialkyl orthoformates also selectively gives corresponding β,γ-unsaturated α-(α-alkoxyalkyl) carbonyl compounds
                                    烯胺很容易由各种羰基化合物制备,在
路易斯酸(如 
BF3·OEt2)存在下与
缩醛或
原甲酸三烷基酯反应,以良好的收率得到相应的 β-烷氧基羰基化合物或 α-二烷氧基甲基羰基化合物。二烯胺与
缩醛或
原甲酸三烷基酯的反应也选择性地以良好的产率得到相应的β,γ-不饱和α-(α-烷氧基烷基)羰基化合物或β,γ-不饱和α-二烷氧基甲基羰基化合物。