Tatsuya Nakai

A synthesis of 4-cyano-hexahydro-2H-benzo [b] quinolizine-7,10-dione as a simple model compound of saframycin A

A simple and efficient synthesis of 4-cyano-8-methoxy-9-methyl-1,3,4,6,11,11a-hexahydro-2H-benzo[b]quinolizine-7,10-dione (20a) as a simple model compound of saframycin A (1) is described starting from the corresponding lactam (16). Reduction of the lactam (16) with lithium aluminum hydride followed by sodium cyanide treatment afforded the α-amino nitrile (19) as an inseparable mixture in an excellent yield. Oxidative demethylation of compound (19) with 10N HNO 3 gave the title compound (20a) and its C-4 epimer (20b). The structure of 20a was confirmed by 1 H nmr and 13 C nmr spectroscopic analysis

SYNTHESIS OF 1,2,4-TRIAZIN-5-ONES THROUGH [4+2] CYCLOADDITION OF 1,2,4-TRIAZA-1,3-DIENES WITH DIPHENYLKETENE

On heating 1,2,4-triaza-1,3-dienes 1 with diphenylketene, [4+2] cycloaddition took place smoothly to afford the corresponding 1,2,4-triazin-5-one derivatives 2 in good yield.