PURPOSE: To obtain (2R)-2-[di(2-propyl)phosphonylmethoxy]-3-p- toluenesulfonyloxy-1-trimethylacetoxypropane for stock of an antiviral agent, etc., by subjecting (2R)-3-O-p-toluenesulfonyloxy-1,2-propanediol to successive esterification, conversion to an acetoxymethoxy deriv. and reaction with a phosphite.
CONSTITUTION: (2R)-3-O-p-toluenesulfonyloxy-1,2-propanediol of formula I is allowed to react with N-trimethylacetylimidazole in a molar ratio of 1:1 in an inert org. aprotic solvent such as dichloromethane in the presence of a tert. amine such as triethylamine. The resultant ester deriv. of formula II is allowed to react with dimethoxymethane and phosphorus pentoxide. The resultant methoxymethoxy deriv. of formula III is allowed to react with acetic anhydride in the presence of a Lewis acid. The resultant acetyl deriv. of formula IV is heated together with bromotrimethylsilane, it is further heated to 100-120°C together with tri(2-propyl) phosphite and the resultant product is purified by chromatography to obtain the objective compd. of formula V.
ANTONIN HORII
HANA DOBOJIYAAKOBAA
