Conformational studies on some 5,6,11,12-tetrahydrodibenzo[b,f][1,4]-diazocine and 11,12-dihydro-6H-dibenzo[b,f][1,4]thiazocine derivatives

Abstract

On the basis of spectroscopic evidence, the favoured conformations of 5,6,11,12-tetrahydrodibenzo[b,f][1,4]diazocine (1a) and its NN′-diacetyl derivative (1b) have been deduced. For the diacetyldibenzodiazocine (1b), interchange between the conformations (II) and (III)[and the equivalent interchange between (I) and (IV)] takes place more readily than that between (I) and (II)[or (III) and (IV)]. The stable conformations of the 5-acetyl-12-methyldibenzodiazocine (1e) have also been deduced; those for N-acetyl-11,12-dihydro-6H-dibenzo[b,f][1,4]thiazocine (2a) are analogous.