A Favorskii-type rearrangement of 1,3-dihalo-3-methyl-2-butanone with enolate of ethyl (diethoxyphosphinyl)acetate or t-butyl (diethoxyphosphinyl)acetate gave ethyl 2-(diethoxyphosphinyl)-5-methyl-3-oxo-4-hexenoate (3a) or its t-butyl ester (3b). Compound 3b was applied to the preparation of (E)-5-methyl-1-(p-tolyl)-1,4-hexadien-3-one and diethyl (4-methyl-2-oxo-3-pentenyl)phosphonate, which are the important intermediates for natural product syntheses.
1,3-二卤-
3-甲基-2-丁酮与乙基(二乙氧基膦酰基)
乙酸酯或叔丁基(二乙氧基膦酰基)
乙酸酯的烯醇酸盐进行Favorskii型重排,得到乙基2-(二乙氧基膦酰基)-5-甲基-3-氧代-
4-己烯酸酯(3a)或其叔丁酯(3b)。化合物3b被用于制备(E)-5-甲基-1-(
对甲苯基)-
1,4-己二烯-3-酮和
二乙基(4-甲基-2-氧代-3-
戊烯基)
膦酸酯,这些是
天然产物合成中的重要中间体。