Glucuronidation of alcohols using the bromosugar–iodonium reagent method

The glycosidation method introduced by Field, employing bromosugars as donors in conjunction with iodine, has been evaluated for glucuronidation. Despite the low donor ability of glucuronates, β-glucuronides were obtained in 70–85% yield from a number of primary alcohols, and in 50–65% from two secondary alcohols, using the pivaloyl compound 11 with NIS as promoter. By contrast, the use of IBr or ICl as promoter gave mainly the α-glucuronides.