N-Alkyl derivatives of trans-6,7-dihydroxy-1,2,3,4,4a,5,10,10b-octahyrobenzo[g]quinoline A congener of apomorphine lacking the non-oxygenated aromatic ring

A synthetic sequence leading to the title compounds began with methyl 5,6-dimethoxy-2-tetralone-3-carboxylate and involved a multi-step construction of the heterocyclic ring. The trans-fused isomer was isolated from the cyclization step. However, the possibility of formation of some cis-fused isomer cannot be precluded.