74984-86-4Relevant articles and documents
The Reaction of Methyl 4,6-O-Isopropylidene-2,3-O-thiocarbonyl-α-D-mannoside with Methyl Iodide: a Synthesis of Methyl α-Tyveloside (Methyl 3,6-Dideoxy-α-D-arabino-hexopyranoside)
Patroni, Joseph J.,Skelton, Brian W.,Stick, Robert V.,White, Allan H.
, p. 987 - 999 (2007/10/02)
The reaction of methyl 4,6-O-isopropylidene-2,3-O-thiocarbonyl-α-D-mannoside with methyl iodide gives two major products, methyl 3,6-dideoxy-3,6-diiodo-2-O-(methylthio)carbonyl-α-D-altropyranoside and methyl 2,3-O-carbonyl-6-deoxy-6-iodo-α-D-mannopyranoside, both of which lack the 4,6-O-isopropylidene grouping but contain the 6-deoxy-6-iodo function, and another minor product.One of the major product, methyl 3,6-dideoxy-3,6-diiodo-2-O-(methylthio)carbonyl-α-D-altropyranoside, is convertedinto methyl α-tyveloside by sequential reduction and ester removal.The incorporation of iodine at C 6 is seemingly due to hydrogen iodide, and may be suppressed in the presence of N,N,N,N-trtramethylnaphthalene-1,8-diamine or propylene oxide, or by the use of 4,6-O-benzylidene-2,3-O-thiocarbonyl-α-D-mannoside as substrate.Methyl iodide/propylene oxide is apparently an efficient combination for thiocarbonate (C=S) into carbonate conversion.The structure of the minor product was shown by single-crystal X-ray diffraction to be 1,6-anhydro-3-deoxy-3-iodo-2-O-(methylthio)carbonyl-β-D-altropyranose.
