Stereoselective synthesis of exocyclic alkenes by Cu-catalyzed allylmagnesiation, Pd-catalyzed alkylation, and Ru-catalyzed ring-closing metathesis: Highly stereoselective synthesis of (Z)- and (E)-gamma-bisabolenes
L. Anastasia et al., Stereoselective synthesis of exocyclic alkenes by Cu-catalyzed allylmagnesiation, Pd-catalyzed alkylation, and Ru-catalyzed ring-closing metathesis: Highly stereoselective synthesis of (Z)- and (E)-gamma-bisabolenes, EUR J ORG C, (16), 2001, pp. 3039-3043
Highly efficient stereoselective syntheses of both (Z)- and (E)-gamma -bisa
bolenes (1) were achieved by ring closing metathesis of stereodefined tetra
substituted alkenes. Both (Z)and (E)-tetrasubstituted alkene precursors wer
e obtained by Cu-catalyzed stereoselective addition of allylmagnesium bromi
de to propargyl alcohols, followed by Pd-catalyzed cross coupling of alkylz
inc derivatives. This represents the first application of ring-closing meta
thesis to the stereoselective synthesis of exocyclic alkenes.