Regioselective syntheses of polycyclic compounds by carbanion-mediated polycyclisation of olefins.
摘要:
This paper reports straightforward syntheses of 1-aryl-bicyclo-[n.1.0]-alkanes, 1-aryl-bicyclo-[3.3.0]-alkanes and of 1-phenyl-1,4-dimethyl-cyclopentane from unsaturated benzylselenides which involve the organolithimus-medicated cyclisation of olefins and poly-olefins.
Arylcycloalkanes have been prepared from acetophenone by a three-step sequence involving the synthesis of α-pheny(ω-alkenyl)methylselenides and their reaction with butyl-lithium reagents to give an intermediate which adds across the CC double bond to give 2-methyl-2-phenylcycloalkylmethyl-lithiums with stereocontrol; other syntheses of these compounds are also described.