Selective mixed coupling of carboxylic acids (II). — photolysis of unsymmetrical diacylperoxides with alkenyl-, halo-, keto-, carboxyl-groups and a chiral α-carbon. Comparison with the mixed kolbe electrolysis
作者:Michael Feldhues、Hans J. Schäfer
DOI:10.1016/s0040-4020(01)97195-9
日期:1985.1
cholanoyl or 3- and 4-carboxyalkanoyl peroxides can be coupled (40 – 70 %). The α-chiral diacyl peroxide ls undergoes the photochemical coupling reaction with 80 % retention of its configuration. The photolysis of diacyl peroxides at −78° C proves to be a favorable supplement of the Kolbe-electrolysis in cases, where the electrolysis fails or produces low yields.
制备烯基酰基和官能化的烷酰基十二烷酰过氧化物,产率为70%至97%,并在-78°C下光解。因此,4至10个烯酰基和4-烷酰过氧化物可提供良好的产率(56 – 68%)的不对称偶联产物。类似地,可以将α-与σ-卤代烷酰基,胆酰基或3-和4-羧基烷酰基过氧化物偶联(40-70%)。α-手性二酰基过氧化物ls经历光化学偶联反应,其构型保留80%。在电解失败或产率低的情况下,在-78°C下二酰过氧化物的光解被证明是Kolbe电解的有利补充。