When stronger base NaOH was used, highly stereoselective products 2-acetyl-3-(Z-4-oxo-2-penten-2-yl)-5-methyl-cis-2,3-dihydrofuran (3) and 5 were obtained in the accelerated reaction with high yields.

• 反应改用氢氧化钠作碱；主要生成化合物5；同时得到2-(4-氧代-2-戊烯基)-3-芳基-4-乙酰基-5-甲基-反-2；3-二氢呋喃(3)；并且反应速度明显加快.