Generation of and cycloaddition to an enantiomerically pure α-oxy-ortho-quinodimethane–tricarbonylchromium complex intermediate
摘要:
The reaction of BunLi with either syn- or anti-eta-6-(1-acetoxycyclobutabenzene)Cr(CO)3 generates under mild conditions the planar chiral ortho-quinodimethane complex intermediate 4 which reacts with dienophiles (methyl acrylate, acrylonitrile, dimethyl fumarate) highly stereoselectively from the face opposite the metal to give the anti-1-hydroxytetrahydronaphthalene-Cr(CO)3 complexes (X-ray structures of 5 and 6) and, after decomplexation, the 1-hydroxytetrahydronaphthalenes 7-14 (asymmetric synthesis of 7 and 8).
Chiral tricarbonyl(η6-cyclobutabenzene)chromium complexes. Diastereoselective synthesis and use in asymmetric cycloaddition reactions
作者:E. Peter Kündig、James Leresche、Lionel Saudan、Gérald Bernardinelli
DOI:10.1016/0040-4020(96)00257-8
日期:1996.5
The intermolecular Diels-Alderreaction of a nonracemic planar chiral (ortho-quinodimethane)Cr(CO)3 intermediate 6 with dienophiles gave, after decomplexation, chiral nonracemic tetralins 23–25. Access to 6 was obtainedvia enzyme catalyzed acetate hydrolysis of 1-acetoxycyclobutabenzene (13), derivatization of the highly enantioenriched 1-hydroxycyclobutabenzene (S-(+)-8) as the tetrahydropyranyl