The synthesis of 14-epi-19-nor-22-oxa-1α,25（OH）2D3 5 was started from diol 8 via Fall＇s method, oxidation, epimerization, protection, coupling with the 19-nor-A-ring 7, and then deprotection of the hydroxyl functi...The synthesis of 14-epi-19-nor-22-oxa-1α,25（OH）2D3 5 was started from diol 8 via Fall＇s method, oxidation, epimerization, protection, coupling with the 19-nor-A-ring 7, and then deprotection of the hydroxyl functions.展开更多
In this paper, it is shown that pterodonoic acid may or may not have the structure of 3-oxoeudesma-4,11-dien-12-oic acid 1 by comparison of their spectral data. But it is certainly not 10-epi-3-oxoeudesma-4,11-dien-12...In this paper, it is shown that pterodonoic acid may or may not have the structure of 3-oxoeudesma-4,11-dien-12-oic acid 1 by comparison of their spectral data. But it is certainly not 10-epi-3-oxoeudesma-4,11-dien-12-oic, acid 2, which is synthesized from dihydrocarvone 3.展开更多
Two new ar-bisabol sequiterpenes,(+)-(7S,10S)-10-epi-7,10-epoxy-3-hydroxy-ar-bisabol-11-ol(1)and(+)-(7R,8R,10S)-10-epi-7,10-epoxy-8-hydroxy-ar-bisabol-11-ol(2),have been isolated by a combination of various column chr...Two new ar-bisabol sequiterpenes,(+)-(7S,10S)-10-epi-7,10-epoxy-3-hydroxy-ar-bisabol-11-ol(1)and(+)-(7R,8R,10S)-10-epi-7,10-epoxy-8-hydroxy-ar-bisabol-11-ol(2),have been isolated by a combination of various column chromatographic techniques including reversed-phase semipreparative HPLC from an ethanol extract of the stem bark of Fraxinus sielboldiana.Their structures were determined by spectroscopic methods including IR,MS,and 1D and 2D NMR experiments.This is the first report of sequiterpenes in the genus Fraxinus.展开更多
文摘The synthesis of 14-epi-19-nor-22-oxa-1α,25（OH）2D3 5 was started from diol 8 via Fall＇s method, oxidation, epimerization, protection, coupling with the 19-nor-A-ring 7, and then deprotection of the hydroxyl functions.
文摘In this paper, it is shown that pterodonoic acid may or may not have the structure of 3-oxoeudesma-4,11-dien-12-oic acid 1 by comparison of their spectral data. But it is certainly not 10-epi-3-oxoeudesma-4,11-dien-12-oic, acid 2, which is synthesized from dihydrocarvone 3.
基金Financial support from the National Natural Sciences Foundation of China(NNSFC,Grant nos.30825044 and 20932007)the National Science and Technology Project of China(Nos.2009ZX09311-004 and 2009ZX09301-003-4-1)is acknowledged.
文摘Two new ar-bisabol sequiterpenes,(+)-(7S,10S)-10-epi-7,10-epoxy-3-hydroxy-ar-bisabol-11-ol(1)and(+)-(7R,8R,10S)-10-epi-7,10-epoxy-8-hydroxy-ar-bisabol-11-ol(2),have been isolated by a combination of various column chromatographic techniques including reversed-phase semipreparative HPLC from an ethanol extract of the stem bark of Fraxinus sielboldiana.Their structures were determined by spectroscopic methods including IR,MS,and 1D and 2D NMR experiments.This is the first report of sequiterpenes in the genus Fraxinus.
