title: Cord-factor analogs: synthesis of 6,6'-di-O-mycoloyl- and -corynomycoloyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside).
abstract: Appropriate solvolysis of 2,3,2',3'-tetra-O-benzyl-4,6,4', 6'-tetra-O-mesyl-alpha,alpha-trehalose gave 2,3,2',3' -tetra-O-benzyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside) (2). Selective tosylation or mesylation of 2 respectively gave the 6, 6'-ditosylate (3) and 6,6'-dimesylate (4), the structures of which were confirmed by the 1H-n.m.r. spectra of the corresponding 4,4'-di-O-acetyl derivatives. Treatment of 3 with potassium mycolate in toluene, and subsequent hydrogenolysis, gave the 6'-mycolate 6-tosylate derivative. Treatment of 3 with potassium mycolate or potassium corynomycolate in hexamethylphosphoric triamide, followed by catalytic hydrogenolysis, yielded the respective cord-factor analogs 6,6'-di-O-mycoloyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside) and 6,6'-di-O-corynomycoloyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside). The same 6,6'-diesters were obtained from the 6,6'-dimesylate 4. Putative 4,6-anhydro-6'-monomycolates are also described.
mesh_terms: D003311:Cord Factors / Q000096:biosynthesis* / Q000138:chemical synthesis*; D006017:Glycolipids / Q000096:biosynthesis* / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009904:Optical Rotation
chemical_list: C043397:6,6'-di-O-mycolyl galactopyranosyl-galactopyranoside; D003311:Cord Factors; D006017:Glycolipids; D007202:Indicators and Reagents; C043398:6,6'-di-O-corynomycolyl galactopyranosyl-galactopyranoside