[CNS-agents: synthesis and properties of 3-anilino-8-oxatropanes]

Reaction of the 8-oxabicyclooctenone and -octanone derivatives 3 and 4 with aniline and metal hydrides yields the 3 alpha-isomers of the aniline derivatives 7 and 8, preferably. The configuration can be determined by NMR-spectroscopy and by cyclization to the scopoline analogue 9b. Depending on the N-substitution the pyran rings of the alpha-isomers are flattened (7,8) or deformed to give a boat conformation (10,11,13). The conformationally restricted aniline derivative 18 can be obtained from 4 with 2-aminobenzaldehyde and diborane, trans-configuration is preferred in 18. Some substrates reveal CNS-effects in mice.