Photooxygenation of (E)-2-methyl-2-butenoic acid derivatives (tiglic acid derivatives) in tetrachloromethane in the presence of catalytic amounts of tetraphenylporphine affords 3-hydroperoxy-2-methylenebutanoic derivatives in generally high yields. Acid-catalyzed cyclodehydration of the 3-hydroperoxy-2-methylenebutanoic acid thus obtained readily gives 5-methyl-4-methylene-3-oxo-1,2-dioxolane, a peroxylactone, in 61% yield. The analogous cyclodehydration of 3-hydroperoxy-2-methylenebutanal [generated in situ by oxygenation of (E)-2-methyl-2-butenal] leads to the formation of 3-hydroxy-5-methyl-4-methylene-1, 2-dioxolane.
在
四苯基卟啉催化剂存在下,将(E)-
2-甲基-2-丁烯酸衍
生物(虎尾
草酸衍
生物)在
四氯化碳中进行光氧化反应,通常可以高产率地得到3-羟基过氧-2-亚甲基
丁酸衍
生物。通过酸催化的环脱
水反应,所获得的3-羟基过氧-2-亚甲基
丁酸容易生成5-甲基-4-亚甲基-3-氧代-1,2-二氧杂
环戊烷(一种过氧内酯),产率为61%。类似地,通过将(E)-
2-甲基-2-丁烯醛就地氧化生成的3-羟基过氧-2-亚甲基
丁醛进行环脱
水反应,则生成3-羟基-5-甲基-4-亚甲基-1,2-二氧杂
环戊烷。