New highly regioselective reactions of unprotected sucrose. Synthesis of 2-O-acylsucroses and 2-O-(N-alkylcarbamoyl)sucroses
摘要:
New methodologies which lead selectively to chosen regioisomeric mono-O-acylsucroses are described. The results indicate that a selective ionization of the free sugar makes the secondary 2-OH group of the glucose moiety more nucleophilic than the primary hydroxyls. New 2-O-acylsucroses 2 and 2-O-(N-alkylcarbamoyl)sucroses 3 were thus obtained in high yields.
Sugar chemistry without protecting groups-III. A facile chemical synthesis of 6-O-acyl-D-glycopyranoses and methyl-6-O-acyl-d-glycopyranosides.
作者:Krystyna Baczko、Daniel Plusquellec
DOI:10.1016/s0040-4020(01)80906-6
日期:——
Regioselective acylation of non protected glycopyranosides was performed using 3- acylthiazolidine-2-thiones 1 and the novel 3-acyl-5-methyl-1,3,4-thiadiazole-2(3H)-thiones 2 as the acylating reagents, yielding 6-O-acylated derivatives in high yields. Acylation of free α-D-glucose and α-D-galactose using the same conditions lead to the 6-O-acylglycoses. This reaction is compared with our previous synthesis
New methodologies which lead selectively to chosen regioisomeric mono-O-acylsucroses are described. The results indicate that a selective ionization of the free sugar makes the secondary 2-OH group of the glucose moiety more nucleophilic than the primary hydroxyls. New 2-O-acylsucroses 2 and 2-O-(N-alkylcarbamoyl)sucroses 3 were thus obtained in high yields.