反应详情

Glc 1β,4 glc is converted to its octaacetate form by conventional methods as disclosed in Methods in Carbohydrate Chemistry 1, 334. A 20 g. portion of this octaacetate is dissolved in 200 ml. of methylene chloride and the solution is cooled to 0° C. An 80 ml. portion of 32% hydrobromic acid in glacial acetic acid is added and the mixture is allowed to stand in an ice bath for 2 hours. The mixture is then poured into crushed ice and diluted with 200 ml. of methylene chloride. The organic layer is separated, washed repeatedly with ice water until neutral, dried over anhydrous sodium sulfate and evaporated in vacuo, giving glc 1β,4 glc heptaacetate bromide as a white solid.

1. additionThe mixture is then poured
2. custominto crushed ice
3. additiondiluted with 200 ml
4. customThe organic layer is separated
5. washwashed repeatedly with ice water until neutral,
6. dry with materialdried over anhydrous sodium sulfate
7. customevaporated in vacuo