A facile method for synthesis of three carbon-homologated carboxylic acid by regioselective ring-opening of β-propiolactones with organocopper reagents
作者:Masatoshi Kawashima、Toshio Sato、Tamotsu Fujisawa
DOI:10.1016/0040-4020(89)80068-7
日期:——
β-carbon-oxygen fission to give 3-substituted propionic acids. Among these three kinds of organocopper reagents, diorganocuprate, especially halomagnesium cuprate gave the highest yields of the acids, which was remarkably observed in the ring-opening of sterically hindered β-propiolactones such as β-methyl- and α,β -dimethyl-β-propiolactones and also in the reactions using the organocopper reagents with vinyl and
在铜(I)盐存在下,有机铜试剂,例如二有机铜酸盐,有机铜-三丁基膦和格利雅试剂,通过区域选择性的β-碳-氧裂变与β-丙内酯反应,生成3-取代的丙酸。在这三种有机铜试剂中,二有机铜酸盐,特别是铜卤化铝的酸收率最高,这在空间受阻的β-丙内酯(如β-甲基-和α,β-二甲基-β)的开环中表现得尤为明显。 -丙内酯,以及在使用带有铜和烯丙基取代基的有机铜试剂的反应中。S N证实β-丙内酯开环通过顺式-α,β-二甲基-β-丙内酯与二叔丁基杯酸酯的反应,β-碳的构型主要转化的2通路,得到syn-2,3,4,4-四甲基戊酸。