Synthesis of eta(6)-(4a-methyl-1,2,3,4-tetrahydro-4aH-carbazole)tricarbonylchromium complex and stereoelectronic behaviour with organolithium reagents: an apparent frontal attack to the (CO)(3)Cr group

The synthesis of eta (6)-(4a-methyl-1,2,3,4-tetrahydro-4aH-carbazole)tricar bonylchromium (3) is described and its reactivity with organolithium reagen ts have been analysed. The addition of RLi (R= H, Me, n-Bu, tert-Bu) to 3 a ffords the corresponding endo/exo tricarbonylchromium complexes of cis-4a-m ethyl-9a-substituted- 1,2,3,4-tetrahydro-4aH-carbazole, which permit the co nsideration of the stereoelectronic behaviour of the tricarbonylchromium gr oup on 4a-methyl and the 9a substituent or on the methylenes of the cyclohe xene moiety in the complexes.