Semisynthetic analogues of ginsenosides, glycosides from ginseng

✍ Scribed by Lyubov N. Atopkina; Vladimir A. Denisenko; Nina I. Uvarova; Georgi B. Elyakov

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 660 KB
• Volume: 177
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(88)85045-6

✦ Synopsis

Glycosylation of the dammar-24-ene-3,12/3,20(S)-triols with 2,3,4,6-tetra-Oacetyl-ar-D-glucopyranosyl bromide (A) in the presence of silver oxide in dichloromethane gives a mixture of the acetylated 3-, 12-, 20-, 3,12-di-, and 3,20-di-@3-Dglucopyranosyl derivatives in a total yield of 83-84.5%. Under similar conditions, the 3-0-acetyl derivatives of dammar-24-ene-3,12&20(S)-triols give a mixture of 12-and 20-0-P-D-glucopyranosyl derivatives. Condensation of betulafolienetriol [dammar-24-ene-3a,12&20(S)-trio11 both with the glycosyl bromide A in the presence of mercuric cyanide in nitromethane and with 3,4,6-tri-O-acetyl-P-Dglucopyranose 1 ,Z(tert-butyl orthoacetate) in the presence of 2,4,6-trimethylpyridinium perchlorate in chlorobenzene under azeotropic distillation results in dehydration and 20-dehydroxyglucosides are formed.