Synthesis of (±)-presqualene alcohol, (±)-prephytoene alcohol, and structurally related compounds
作者:Rodwill V. M. Campbell、Leslie Crombie、David A. R. Findley、Richard W. King、Gerald Pattenden、Donald A. Whiting
DOI:10.1039/p19750000897
日期:——
The stereochemistry of the base-catalysed addition–elimination method for cyclopropane ring synthesis, employing a βγ-unsaturated phenyl sulphone and an αβ-unsaturated ester, has been examined. The olefinic geometry of the βγ-unsaturated sulphone is retained in the product, and the unsaturated side chain and the ester function emerge trans about the ring, with substantial stereoselectivity. On the
对于环丙烷环合成的碱催化加成-消除方法的立体化学,采用β γ不饱和苯基砜和αβ不饱和酯,已审查。的烯烃几何β γ不饱和砜被保留在产品中,和不饱和侧链和酯官能团出现反式围绕该环,具有相当大的立体选择性。另一方面,αβ-不饱和酯的双键的几何形状在阴离子加成产物中达到平衡。因此,基于原始αβ-不饱和酯的几何形状,在没有立体选择偏好的情况下产生了所得的环丙烷。这项工作已导致合成乙基2,2-二甲基-反式-3-[(1E,5 E)-2,6,10-三甲基十一碳烯-1,5,9-三烯基]环丙烷羧酸盐(40)和相应的环丙基甲醇(42),代表角鲨烯分子的一侧,和对C-2差向异构二萜类化合物2-[((E))-4,8-二甲基壬基-3,7-二烯基] -2-甲基-反式-3-(2-甲基丙-1-烯基)环丙烷羧酸酯(44)和(45)以及相应的醇(47)和(48),代表角鲨烯分子的另一侧。还研究了较低的异戊二烯。