HYDROACRIDINES XVIII - SYNTHESIS AND NMR SPECTROSCOPIC INVESTIGATION OF ,8A-BETA,9A-ALPHA,10A-BETA)-TETRADECAHYDROACRIDINE AND SOME OF ITS DERIVATIVES

The reductive amination of (R,R*)-2,2'-methylene-bis-cyclohexanone (1 ) with methylamine and potassium borohydride affords a mixture of (4a alpha,8a beta,9a alpha,10a beta)- and (4a alpha,8a alpha,9a beta,10a a lpha)-tetradecahydro-10-methylacridine (2, 3) in a ratio of approximat ely 1.3:1 in 57% overall yield. By N-demethylation of 2, via the N-nit rosamine 4 the first synthesis of (4a alpha,8a beta,9a alpha,10a beta) -tetradecahydroacridine (5) could be performed. The relative configura tions and conformations of compounds 2-5 as well as the barrier of con formational inversion of 5(Delta G(300)(#), = 55.5 +/- 0.4kJ.mol(-1)) were determined by NMR spectroscopy.