摘要:
The ring contraction reaction of 2-O-(trifluoromethyl)sulfonyl]oxy]-beta-D-glucopyranosides and their corresponding a-anomers is reported. The rearrangement was shown to occur under extremely mild basic conditions to allow isolation of acid-sensitive optically active substituted cyclopropylmethanols. The chiral auxiliary can be regenerated by converting the C-glucofuranoside, byproduct of the rearrangement, into tri-O-benzyl-D-glucal (two steps).