C-Glycosides. 9. Stereospecific Synthesis of C-Glycosidic Spiroketal of the Papulacandins

Article abstract of DOI:10.1021/jo00022a014

The reaction of ortho-lithiated triphenylmethyl benzyl ether with perbenzylated D-gluconolactone 1 followed by cyclization by BF3*Et2O provides a new stereospecific synthesis of C-glycosidic spiroketals.The structure of the peracetylated derivative was determined by X-ray diffraction.This methodology is applied to the synthesis of the spiroketal unit of papulacandins.