✦ LIBER ✦
Synthesis of mosesin-4, a naturally occurring steroid saponin with shark repellent activity, and its analog 7-β-galactosyl ethyl cholate
✍ Scribed by Dario Gargiulo; Timothy A. Blizzard; Koji Nakanishi
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- French
- Weight
- 617 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
The fit synthesis of mosesin-(13). a naturally occurring steroid saponin with shark repellent activity, and its analog 19, is described. They both possess a free galactose residue attached axially at the 7a position of the steroidal aglycon. Methyl cholate 3cathylate (2) was used as a model for exploring various several methods to glycosidate the severely hindered 7a-position. Best results were obtained with j3-galactose pentacetate (3a). using trimethylsilyl triflate as a promoter, in l,Zdichlomethane, at -20" C, for 14 hours,