Tricarbonylchromium complexes of 2-aminotetralin derivatives. Part 2. Regio- and stereo-selective reactions

Abstract

Methyl and trimethylsilyl substituents have been introduced in the C-7- and C-6-positions of tricarbonylchromium complexes of C-8-oxygenated 2-(dipropylamino)tetralin derivatives. The C-6-substituted regioisomers were produced from a complex with a bulky triisopropylsilyloxy C-8-substitutent whereas C-7-derivatives were produced from the C-8-methoxy substituted complex. The reactions proceed with high regioselectivities. Treatment of endo-tricarbonyl [2-(dipropylamino)-8-methoxytetralin] chromium with Bu^tOK and Mel in DMSO lead to introduction of a C-1-methyl group located trans to the C-2-substituent and anti to the tricarbonylchromium moiety. In contrast, a methyl group was introduced in the C-4-position, cis to the C-2-substituent and anti to the tricarbonylchromium moiety, when the diastereoisomeric exo complex was submitted to the same conditions.