Preparation of 4,4a,9,9a-tetrahydrocarbazoles and 1,3a,4,8b-tetra- hydrocyclopenta[b]indoles

Article abstract of DOI:10.1007/s10593-006-0199-7

Halocyclization of mesylates or tosylates of 2-(cycloalk-2-en-1-yl)anilines gives N-methanesulfonyl-or N-toluenesulfonyl-1-halo-1,2,3,4,4a,9a- hexahydrocarbazoles, heating of which in DMF at 160°C or in piperidine at 110°C leads to 4,4a,9,9a-tetrahydro-3H