The cinnamoyl- (1a-j) and (5-phenyl-2,4-pentadienoyl)- (1k) ketene dithioacetals are shown to undergo methanolysis in the presence of ether-boron trifluoride complex and mercury(II) chloride to the corresponding methyl 5-aryl-3-oxo-4-pentenoates 2a-j and 3-oxo-7-phenyl- 4,6-heptadienoate (2k), respectively, in good yields. However, the corresponding (2-methylcinnamoyl)ketene dithioacetals 3a-f, under identical reaction conditions, undergo Nazarov cyclization to give the corresponding substituted cyclopentenones 4a-f.
香豆醯基(1a-j)和(5-苯基-2,4-
戊二烯酰基)(1k)酮烯二
硫乙酰醇在醚-
三氟化硼复合物和
氯化
汞存在下进行
甲醇解,得到相应的甲基5-芳基-3-氧-
4-戊烯酸酯2a-j和3-氧-7-苯基-4,6-庚二烯酸酯(2k),产率良好。然而,相应的(2-甲基香豆醯基)酮烯二
硫乙酰醇3a-f在相同反应条件下发生纳扎罗夫环化反应,生成相应的取代
环戊烯酮4a-f。