Constituents of Rhizoma Nupharis. XVIII. Synthesis of Alkaloids from <I>Nuphar japonicum</I> DC. I. Synthesis of <I>rac</I>-Deozynupharidine
作者:Yoshio Arata、Toshiko Nakanishi、Yoko Asaoka
DOI:10.1248/cpb.10.675
日期:——
Condensation of octahydro-4-quinolizinone (I) and ethyl 3-furoate affords (II) which, on being heated with dilute hydrochloric acid, forms a compound (IV) of hexahydroquinolizine series. Reduction of (IV) with sodium borohydride gives (V) which is separated into two kinds of racemate showing infrared absorption band due to trans-quinolizidine. By the route shown above, (XVII) was obtained from 1, 7-dimethyloctahydro-4-quinolizinone (XII) and (XVII) was separated into three kinds of bases. From the result of infrared spectral measurement, (XVIIa) and (XVIIc) were assumed to be trans-quinolizidine compound and (XVIIb) was assumed to be cis-quinolizidine compound. The infrared spctra (in carbon tetracbloride solution) of (XVIIa) and (-)-deoxynupharidine isolated from Nuphar japonicum DC. were found to be entirely identical and (XVIIa) was concluded to be rac-Deoxynupharidine.
八氢-4-喹嗪酮(I)和 3-糠酸乙酯缩合后得到(II),用稀盐酸加热后形成六氢喹嗪系列化合物(IV)。用硼氢化钠还原(IV)得到(V),(V)被分离成两种外消旋体,显示出反式喹嗪的红外吸收带。通过上述路线,从 1,7-二甲基八氢-4-喹嗪酮(XII)中得到了(XVII),(XVII)被分离成三种碱。根据红外光谱测量结果,(XVIIa) 和 (XVIIc) 被认为是反式喹嗪化合物,(XVIIb) 被认为是顺式喹嗪化合物。从 Nuphar japonicum DC.中分离出来的 (XVIIa) 和 (-)-deoxynupharidine 的红外光谱(在四氯化碳溶液中)完全相同,因此 (XVIIa) 被认为是 rac-Deoxynupharidine。