| 摘要 |
There is a known process for the preparation of 1,6-dichloro-1,6-dideoxy-.beta.-D-fructofuranosyl-4-chloro-4-deoxy-a-galactopyranoside by reacting sucrose with a tritylating agent, acetylating the tritylated reaction product with an acetylating agent to obtain 6,1',6'-tri-O-tritylsucrose penta-acetate, detritylating the 6,1',6'-tri-O-tritylsucrose penta-acetate to obtain 2,3,4,3',4'-penta-O-acetylsucrose, isomerizing the 2,3,4,3',4'-penta-O-acetylsucrose to obtain 2,3,6,3',4'-penta-O-acetylsucrose, chlorinating the latter product with a chlorinating agent to obtain 4,1',6'-trichloro-4,1',6.-trideoxygalactosucrose pentaacetate, and deacetylating the chlorinating product. According to the invention, the chlorinating step utilises a chlorinating agent selected from the group consisting of triphenylphosphine oxide/thionyl chloride, triphenylphosphine oxide/phosgene, triphenylphosphine sulfide/thionyl chloride and triphenylphosphine sulfide/phosgene in the presence of an aromatic hydrocarbon solvent at a temperature up to about 120.degree.C. This chlorinating agent is efficient and eliminates the use of a pyridine as a solvent. |
