In the trichloroacetimidate method of Richard R. Schmidt, the peracetylated "O"-(α--glucopyranyl) trichloroacetimidate forms with 1-octanethiol via boron trifluoride-etherate catalysis upon inversion exclusively "n"-octyl-1-thio-β--glucopyranoside (after deacetylation), while the perbenzylated "O"-(α--glucopyranyl) trichloroacetimidate is converted upon retention to the "n"-octyl-1-thio-α--glucopyranoside (after debenzylation).