Scopul nostru este sprijinirea şi promovarea cercetării ştiinţifice şi facilitarea comunicării între cercetătorii români din întreaga lume.
Autori: E.Sisu, I. Sisu, C. Csunderlik, V. Rusu
Editorial: Rev.Chim., 53(3), p.193-197, 2002.
This paper presents the seven step synthesis of phenyl-6-O-benzyl-2-deoxy-2-phthalimido-4-O-(2,3,4,6-tetra-O-acetyl--D-galactopyranosyl)-1-thio--D-glucopyranoside (lactose block) starting from glucosamine hydrochloride and galactose acetyl halide with a global yield of 32.5%. The coupling reaction between galactose acetyl halide and phenyl-6-O-benzyl-2-deoxy-2-phthalimido-1-thio--D-glucopyranoside takes place after Koenigs-Knorr method, using silver triflate as promoter. Best results were obtained by using anhydrous condithions (molecular sieve 4A) and in the absence of bases that favour the formation of orthoesthers as secondary products. The 1H-NMR (300 MHz) spectra of the intermediates and the final product are also presented.
Cuvinte cheie: Lactose block, Silver triflate, Koenigs-Knorr reaction,1H-NMR