A highly stereocontrolled formal total synthesis of (±)- and of (−)-grandisol by 1,4-conjugated addition of organocopper reagents to cyclobutylidene derivatives
作者:Angela M. Bernard、Angelo Frongia、Jean Ollivier、Pier Paolo Piras、Francesco Secci、Marco Spiga
DOI:10.1016/j.tet.2007.03.134
日期:2007.6
Starting from suitable cyclopropanes, a formal total synthesis of racemic grandisol and of the enantiopure (−)-grandisol is presented. The racemic synthesis of the grandisol precursor was accomplished in five steps. The synthesis of the chiral non-racemic precursor (1S,2S,2′R)-cis of this pheromone was realized in 10 steps, with an overall yield of 45%, using the enantiopure cyclobutanone (R,S), previously
从合适的环丙烷开始,提出了外消旋大扁豆酚和对映纯(-)-大扁豆酚的正式全合成。Grandisol前体的外消旋合成可通过五个步骤完成。手性非外消旋前体的合成(1小号,2小号,2' - [R此信息素) -顺在10个步骤中实现的,具有45%的总产率,使用对映纯的环丁酮([R ,小号),先前通过光学纯的氧杂螺环戊烷的扩环获得。关键的立体定义步骤是向手性α,β-不饱和环丁烯羰基衍生物中添加二甲基铜锂。