REGIO- AND STEREOSELECTIVE GLYCOSYLATION OF 20(S),24(R)-EPOXYDAMMARANE-3,12β,25-TRIOLS WITH CHOLESTERYL (α-D-GLUCOSE ORTHOACETATE). III.

Article abstract of DOI:10.1007/BF00579764

The glycosylation of 20(S),24(R)-epoxydammarane-3,124b,25-triols under the conditions of the previous formation of an ion pair with a Lewis acid and subsequent treatment with cholesteryl (α-D-glucose orthoacetate) leads to the selective formation with high yields of the corresponding 12-monoglucosides having the trans configuration of the glucosidic bond.The regioselectivity of the direct glycosylation of 20(S),24(R)-epoxydammarane-3,12β,25-triols by orthoesters is determined by the influence of intramolecular hydrogen bonds in the initial triols.Details of the PMRand 13C NMR spectra of the new compounds obtained are given.