作者:J. Bertrand、L. Gormchon、P. Mahoni
DOI:10.1016/0040-4020(84)85094-2
日期:1984.1
Regio and stereochemistry in the addition of preformed magnesium and lithium ketone enolates (1 to 8) to α-enones (10 and 11) have been examined. When the substitution degree of the enolate is increased the formation of δ-diketone is favoured; nevertheless a good efficiency in the synthesis of the γ-ethylenic β-ketols (1-2 addition) is obtained via bromomagnesium enolates (EMgX) under kinetic conditions
已经研究了在α-烯酮(10和11)中添加预先形成的镁和锂酮烯醇酸酯(1至8)的区域和立体化学。当烯醇化物的取代度增加时,倾向于形成δ-二酮;反之,则增加。然而,在动力学条件下通过溴化镁烯醇盐(EMgX)获得了合成γ-烯属β-酮醇的良好效率(1-2加成)。烯醇锂(ELi),主要是烯醇镁(E 2 MgX)优先提供迈克尔加成。通常观察到从1-2加到1-4的可逆性,但使用EMgBr或E 2时,非对映异构体δ-diLetones的立体化学(如果有)镁为起始烯醇化物。