Silver(I) oxide-mediated regioselective 2-monoacylation in 3-O-benzyl-alpha-L-rhamnopyranosides and application in synthesis of a protected tetrasaccharide fragment of potent cytotoxic saponins gleditsiosides C and D.
The axial 2-hydroxyl group of methyl and allyl 3-O-benzyl-alpha-L-rhamnopyranosides was selectively acylated in 56-78% yields by reaction with 1.1 equiv of acyl chloride in the presence of 1.5 equiv of silver(I) oxide. Use of the method permitted a convenient synthesis of a protected tetrasaccharide fragment of triterpene saponins gleditsiosides C and D.
Yang
Qian
Q
Department of Chemistry of Medicinal Natural Products and Key Laboratory of Drug Targeting of the Ministry of Education, School of Pharmacy, Sichuan University, Chengdu 610041, PR China.
Lei
Ming
M
Yin
Qin-Jian
QJ
Yang
Jin-Song
JS
D000215:Acylation; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D012210:Rhamnose / Q000737:chemistry; D012503:Saponins / Q000138:chemical synthesis* / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D005960:Glucosides; D009844:Oligosaccharides; D010087:Oxides; D012503:Saponins; D018030:Silver Compounds; C040225:disilver oxide; D012210:Rhamnose