Synthesis and stereochemistry of 8,13-diaza-2,3-dimethoxygona-1,3,5(10),9(11)-tetraen-12-one and d-homo derivatives

From the condensation reaction of O-methylbutyrolactim ( 2), O-methylvalerolactim ( 3), O-methylcaprolactim ( 4) and O-methyl-4- t-butylcaprolactim ( 5) with ethyl 6,7-dimethoxy-α-[1-(1,2,3,4-tetrahydro-isoquinolyl)]acetate ( 1), 8,13-diaza-2,3-dimethoxygona-1,3,5(10),9(11)-tetraen-12-one ( 6) d-homo-derivatives ( 7–9), and medium-sized ring cyclic diamides ( 10,11) were obtained. The stereoselective reduction of compounds 6–9 by Adam’s platinum catalyst afforded 8,13-diaza-2,3-dimethoxygona-1,3,5(10)-trien-12-one ( 12) and its d-homo derivatives ( 13–15). The structures of the compounds obtained were established by NMR and X-ray crystallographic analyses.