Construction of fused bicyclo-[5.3.0]decane and -[5.4.0]undecane ring skeletons via sequential additions of nucleophiles to tricarbonyltropyliumchromium tetrafluroborate

Abstract

The addition of a variety of the highly functionalized zinc–copper reagents RCu(CN)ZnI to the title cation gives (η⁶-cyclohepta-1,3,5-triene)Cr(CO)₃ complexes with a functionalized side chain at the C-7 position of the ring: intramolecular cyclisation of ester-substituted adducts using lithium diisopropylamide generates fused bicyclo-[5.3.0]decane and -[5.4.0]undecane derivatives.