DIASTEREOSELECTIVE SYNTHESIS OF THE BENZOXAZINONE ACETAL GLUCOSIDE ENT-GDIMBOA - THE FIRST ENANTIOMER OF A NATURAL ACETAL GLUCOSIDE

The synthesis of y-4-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one, th e enantiomer of the natural acetal glucoside GDIMBOA from maize, has b een achieved by the double diastereoselective L-glucosylation of racem ic ,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one with 2,3,4,6-tet ra-O-acetyl-beta-L-glucopyranosyl trichloroacetimidate in the presence of excess of boron trifluoride etherate as promoter as well as protec ting and equilibrating agent. (C) 1997 Elsevier Science Ltd.