“…Alkylations of carboxylic acids 29 and alcohols 30 with alkyl halides are also facilitated by HgO·2HBF 4 . Mercury(II) oxide and HBF 4 in alcohol effected mild solvolysis of 2-hydroxytrithioorthoesters to yield αhydroxycarboxylic esters in high yield 31. See also Mercury(II) Oxide-Tetrafluoroboric Acid.…”