28954-20-3Relevant academic research and scientific papers
Regioselective methylation of methyl glycopyranosides with diazomethane in the presence of transition-metal chlorides and of boric acid
Evtushenko, Evgeny V.
, p. 187 - 200 (2007/10/03)
Partial methylation of the methyl pyranosides of a number of pentoses, hexoses, 6-deoxyhexoses, methyl uronates and their methyl ethers with diazomethane in the presence of transition-metal chlorides and boric acid was studied. It was found for methyl glycosides of pentoses and 6-deoxyhexoses that tin(II), antimony(III), and titanium(IV) chlorides as well as boric acid promoted substitution mainly of OH-3, but with cerium(III) and zinc(II) salts mainly substitution of OH-2 was observed. Methylation of methyl β-l-rhamnopyranoside demonstrated higher reactivity of OH-2 in all cases. The methylation of methyl glycosides of hexoses in the presence of tin(II), antimony(III) and cerium(III) chlorides gave mainly 3-methyl ethers. The 3-methyl ethers, which are not involved in further complexation, accumulated up to 50-80% of the reaction mixture (95-100% of monomethyl ether fraction). Convenient preparative syntheses of methyl ethers for a number of sugars are suggested. Copyright (C) 1999 Elsevier Science Ltd.
METHYLATION OF METHYL α-D-HEXOPYRANOSIDES WITH DIAZOMETHANE IN THE PRESENCE OF A SMALL AMOUNT OF WATER
Inoue, Yuko,Nagasawa, Kinzo
, p. 181 - 190 (2007/10/02)
The long-time reaction of methyl α-D-gluco-, α-D-manno-, and α-D-galactopyranosides with excess diazomethane-diethyl ether at 25 deg C the presence of water gave all partially methylated methyl α-D-hexopyranosides which differ in number and position of methyl substitution.The presence electrolytes, such as potassium or sodium phosphate, in the reaction medium enhanced the degree of methylation, resulting in preferential formation of tri-O-methyl derivatives of methyl α-D-hexopyranosides.
