Stereocontrolled oxycarbonylation of 4-benzyloxyhepta-1,6-diene-3,5-diols promoted by chiral palladium(II) complexes

The synthesis of all diastereomers of 4-benzyloxyhepta-1,6-diene-3,5-diols 8-10 is described. The diastereo- and enantioselectivity of palladium(II)-catalysed oxycarbonylation of the symmetric compounds 8-10 were studied. The substrates 8-10 underwent Pd(II)-initiated oxycarbonylative bicyclisation to afford bicyclic lactones 11-14 in good yields and with excellent threo-diastereoselectivity. Additionally, the synthesis of enantiomerically pure lactone D-gluco-12, precursor for syntheses of goniofufurone and 7-epi-gonio-fufurone, was developed. (c) 2007 Elsevier Ltd. All rights reserved.