Diisopropylethylamine → 2,5-anhydro-1-C-(diethoxyphosphinyl)-3,4,6-tris-O-(phenylmethyl)-1-O-[[2-(trimethylsilyl)ethoxy]methyl]-D-mannitol

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Reaction Steps

In accordance with Flowchart C, 2,5-anhydro-3,4,6-tris-O-(phenylmethyl)-D-mannose 4 is reacted with diethyl phosphite and sodium ethoxide under argon, giving [lR(and/or IS)]-2,5-anhydro-1-C-(diethoxyphosphinyl)-3,4,6-tris-O-(phenylmethyl)-D-glucitol 21, which is reacted with N,N-diisopropylethylamine and 2-(trimethylsilyl)ethoxymethyl chloride in dry dichloromethane under argon at reflux, giving [1R-(and/or 1S)]-2,5-anhydro-1-C-(diethoxyphosphinyl)-3,4,6-tris-O-(phenylmethyl)-1-O-[[2-(trimethylsilyl)ethoxy]methyl]-D-mannitol 22. Compound 22 is hydrogenated in methanol over palladium hydroxide on carbon, giving [lR(and/or lS)]-2,5-anhydro-1-C-(diethoxyphosphi8nyl)-1-O-[[2-(trimethylsilyl)ethoxy]methyl]-D-mannitol 23 which is then reacted with diphenyl chlorophosphate in pyridine at ice bath temperature, giving [1R(and/or 1S)]-2,5-anhydro-1-C-(diethoxyphosphinyl)-1-0-[[2-(trimethylsilyl)ethoxy]methyl]-D-mannitol, 6-(diphenyl phosphate) 24. Compound 24 is reacted with boron trifluoride etherate in anhydrous acetonitrile under argon, giving [1R(and/or 1S)]-2,5-anhydro-1-C-(diethoxyphosphinyl)-D-mannitol, 6-(diphenyl phosphate) 25 which is then reacted with bromotrimethylsilane in deuterated chloroform under argon, giving [1R(and/or 1S)]-2,5-anhydro-1-C-phosphono-D-mannitol, 6-(diphenyl phosphate) 26 which is hydrogenated in methanol over platinum oxide, giving [1R(and/or 1S)]-2,5-anhydro-1-C-phosphono-D-mannitol, 6-(dihydrogen phosphate) 27. ##STR12##

Provenance & Evidence