Generation of and cycloaddition to an enantiomerically pure α-oxy-ortho-quinodimethane–tricarbonylchromium complex intermediate

Abstract

The reaction of BuⁿLi with either syn- or anti-η⁶-(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).