Methyl α- and β-D-galactopyranosides and 4-O-β-D-galactopyranosyl-3,6-anhydro-L-galactose dimethylacetal were sulfated with sulfuric acid and dicyclohexylcarbodi-imide as a condensation reagent. The sulfated sugars were isolated by ion-exchange chromatography, characterized, and assigned by methylation analyses. On the basis of the yield of each sulfated product that was isolated, sulfation on O-6 appeared to be predominant.
(EN) $i(Inter alia), a direct method for the regioselective sulfation of an organic molecule having optionally derivatized hydroxyl groups at least on two adjacent carbon atoms characterised in that it comprises the treatment of a di-(optionally substituted alkyl and/or aryl) stannylene acetal derivative thereof with an electrophilic sulfating agent is disclosed.(FR) L'invention concerne entre autres un procédé direct de sulfatation régiosélective d'une molécule organique ayant éventuellement des groupes dérivés hydroxyle au moins sur deux atomes de carbone adjacents, et se caractérisant en ce qu'il comprend le traitement d'un dérivé d'acétal de stannylène di(alkyle et/ou aryle éventuellement substitué) avec un agent de sulfatation électrophile.
Development of a protecting group for sulfate esters
作者:Andrew D. Proud、Jeremy C. Prodger、Sabine L. Flitsch
DOI:10.1016/s0040-4039(97)01681-x
日期:1997.10
The trifuoroethyl ester was studied as a protection group for sulfate monoesters in carbohydrates. The ester was formed from the sulfate by treatment with trifluorodiazoethane and was compatible with other common protectinggroups used in carbohydrate chemistry. Selective cleavage of the trifluoroethyl ester was achieved with potassium t-butoxide.