| 摘要 |
NEW MATERIAL:A compound of formula I (R is lower alkyl). EXAMPLE:Methyl threo-2,3-dihydroxy-3-(4-methoxyphenyl)-propionate. USE:A synthetic intermediate of the compound of formula II which is used as remedy for stenocardia or essential hypertension. PREPARATION:A compound of formula I is oxidized with, e.g., a permanganate salt to give the compound of formula I readily in high yield and high yield with industrial advantage. The amount of the oxidizing agent is 1-2 times the molar quantity of the compound of formula III. The reaction is carried out at -80-+60 deg.C for 1hr to 20 days. The compound of formula I is subjected to dehydration reaction with 2-nitrothiophenol in a solvent in the presence of a Lewis acid to form a mixture of threo and erythro isomers. Then, the mixture is purified to isolate a compound of formula IV and the compound is subjected to synthetic reactions in order to give the compound of formula II.
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