title: Cord-factor analogs: synthesis of 6,6'-di-O-mycoloyl- and -corynomycoloyl-(alpha-D-mannopyranosyl alpha-D-manno-pyranoside).
abstract: Selective triflation of 4,6:4',6'-di-O-benzylidene-alpha,alpha-trehalose gave 4,6:4',6'-di-O-benzylidene-2,2'-di-O-triflyl-alpha,alpha-trehalose , the structure of which was confirmed by the 1H-n.m.r. spectrum of its 3,3'-di-O-acetyl derivative (4). Treatment of 4 with sodium nitrite in hexamethylphosphoric triamide, followed by benzylation, afforded 2,3,2',3'-tetra-O-benzyl-4,6:4',6'-di-O-benzylidene-(alpha-D-mannopyrano syl alpha-D-mannopyranoside (7). Removal of the two benzylidene groups from 7, and selective tosylation of the product, gave a mixture of the 6,6'-ditosylate (11) and the 6-monotosylate (12), which were separated by chromatography. Treatment of 11 with potassium corynomycolate or potassium mycolate afforded the corresponding 6,6'-diesters, 14 and 15, respectively. Treatment of the monotosylate 12 with potassium corynomycolate gave the 6-monoester 18. Catalytic hydrogenolysis of 14, 15, and 18 gave the respective cord-factor analogs.
mesh_terms: D003311:Cord Factors / Q000138:chemical synthesis*; D004187:Disaccharides / Q000138:chemical synthesis*; D006017:Glycolipids / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009904:Optical Rotation; D013329:Structure-Activity Relationship
chemical_list: D003311:Cord Factors; D004187:Disaccharides; D006017:Glycolipids; D007202:Indicators and Reagents; C042620:6,6'-di-O-mycoloyl-alpha-mannopyranosyl-alpha-mannopyranoside; C042619:6,6'-di-O-corynomycoloyl-alpha-mannopyranosyl-alpha-mannopyranoside