Acta Chimica Sinica ›› 1983, Vol. 41 ›› Issue (1): 95-96. Previous Articles    

Original Articles

雪胆甲素在碱中的乙酰基转移反应

王方材;梁晓天   

  1. 云南省药品检验所;中国医学科学院药物研究所
  • 出版日期:1983-01-15 发布日期:1983-01-15

Tcetyl migration of 25-0-acetyl-23, 24-dihydrocucurbitacin F by alkali treatment.

WANG FANGCAI;LIANG XIAOTIAN   

  • Online:1983-01-15 Published:1983-01-15

23, 24-Dihydrocucurbitacin F (2) and its 25-ester (1) are antibacterial bitter principles isolated from Hemsleya amabilis Diels. Upon brief treatment with ethanolic potassium hydroxide under reflux, compound 1 undergoes facile acetyl migration from oxygen to carbon with the formation of 23-acetyl-23, 24-dihydrocucurbitacin F (3), to the exclusion of any saponification. The relatively hindered ester group of 1 is evidently less prone to saponification, thus bringing an internal attack by the 23-enolate anion to the fore. The structure of 3 was deduced from spectral evidence and mechanistic considerations, and confirmed by the cleavage of the acetyl group with refluxing Claisen's alkali. The resultant compound 2 was thus obtained form 1 only via a circuitous route.

Key words: TRITERPENE, ACETYL GROUP, HEMSLEYA AMABILIS, TRANSFER REACTIONS, DIGYAROCUCURBITACIN F

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