Chemoselective synthesis of sialic acid 1,7-lactones.
The chemoselective synthesis of the 1,7-lactones of N-acetylneuraminic acid, N-glycolylneuraminic acid, and 3-deoxy-d-glycero-d-galacto-nononic acid is accomplished in two steps: a simple treatment of the corresponding free sialic acid with benzyloxycarbonyl chloride and a successive hydrogenolysis of the formed 2-benzyloxycarbonyl 1,7-lactone. The instability of the 1,7-lactones to protic solvents has been also evidenced together with the rationalization of the mechanism of their formation under acylation conditions. The results permit to dispose of authentic 1,7-sialolactones to be used as reference standards and of a procedure useful for the preparation of their isotopologues to be used as inner standards in improved analytical procedures for the gas liquid chromatography-mass spectrometry (GLC-MS) analysis of 1,7-sialolactones in biological media.
Allevi
Pietro
P
Dipartimento di Chimica, Biochimica e Biotecnologie per la Medicina, Università degli Studi di Milano, Via Saldini 50, I-20133 Milano, Italy.
Rota
Paola
P
Scaringi
Raffaella
R
Colombo
Raffaele
R
Anastasia
Mario
M
D002236:Carbohydrate Conformation; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D012794:Sialic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D007783:Lactones; D012794:Sialic Acids