Sulfonation of unsaturated compounds. I. Sulfonation of branched chain ketones with sulfur trioxide. One-step synthesis of tetramethylene sulfate through a retro pinacol-type) rearrangement
Cyclic sulphates of formula: ##STR1## are prepared by oxidation of a cyclic sulphite of formula: ##STR2## with a hypohalite of an alkali or alkaline-earth metal and a catalytic quantity of a ruthernium derivative (RuO.sub.2, RuCl.sub.3). In formulae (I) and (II), R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are identical or different and each represents hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy or alkoxycarbonyl.
Alkylation of alcohols, amines, thiols and their derivatives by cyclic sulfate intermediates
申请人:ISIS Pharmaceuticals, Inc.
公开号:US06277982B1
公开(公告)日:2001-08-21
Methods for the alkylation of alcohols, amines and thiols by the use of cyclic sulfates are disclosed. The alkylated sulfates formed are versatile intermediates which may be further elaborated by methods of the invention. In particular, methods for the alkylation of the 2′, 3′ or 5′-hydroxy position of nucleosides and nucleoside analogs with cyclic sulfates to form the 2′, 3′ or 5′-O-alkyl sulfate modified compounds are disclosed. Displacement of the 2′,3′ or 5′-O-sulfate with a nucleophile provides 2′, 3′ or 5′-O-modified nucleosides and nucleoside analogs useful for the synthesis of oligomeric compounds having improved hybridization affinity and nuclease resistance.