Synthesis of 9-Substituted Tetrahydrodiazepinopurines: Studies toward the Total Synthesis of Asmarines
作者:Doron Pappo、Shiri Shimony、Yoel Kashman
DOI:10.1021/jo048622g
日期:2005.1.1
A methodology for the preparation of asmarine analogues has been developed. The asmarines are cytotoxic marine alkaloids with a unique tetrahydro[1,4]diazepino[1,2,3-g,h]purine (THDAP) structure. Three cyclization methods were applied for the preparation of the 9,9-disubstituted 10-hydroxy-THDAP system, namely, aminomercurization, iodocyclization, and acid-catalyzed cyclization. The DMPM group of the NOH functionality and cyanoethyl group of the N-9 atom were found to be the most suitable protecting groups. The structures of all compounds were mainly determined from NMR measurements including N-15 chemical shifts obtained from (NH)-N-15 HMBC spectra. The end products are at least about 1 order of magnitude less active than the natural product asmarine B.
Synthesis of 9-substituted tetrahydrodiazepinopurines—asmarine A analogues
作者:Doron Pappo、Yoel Kashman
DOI:10.1016/s0040-4020(03)01058-5
日期:2003.8
unique tetrahydro[1,4]diazepino-[1,2,3-g,h]purine (THDAP) structure and interesting biological properties. Three synthetic approaches were employed for the preparation of the THDAP system. Several N-9, of the purine, protecting groups were investigated. 15N-Chemical shifts measured from 15NH HMBC experiments for several compounds, that demonstrate the influence of various structural features on the 15N-resonances