Synthetic method for (4R,5R)-2-bischloromethyl-4,5-dihydro-5-(4-methylsulfonyl)-4-oxazole methyl alcohol

The invention belongs to the technical field of synthesis of a florfenicol intermediate and particularly relates to a synthetic method for (4R,5R)-2-bischloromethyl-4,5-dihydro-5-(4-methylsulfonyl)-4-oxazole methyl alcohol. The method comprises the following steps that a sodium hydroxide water solution is added into 2-nitro ethyl alcohol in a dripped mode, then bromine is added, and the reaction is carried out to obtain 2-bromine-2-nitro ethyl alcohol; 2-bromine-2-nitro ethyl alcohol and ethyl alcohol are obtained, a hydrogenation catalyst is added, the mixture reacts with hydrogen, alcohols solvent is added, and then dichloroacetonitrile is added in a dripped mode for reaction; magnesium, tetrahydrofuran and 4- methylsulfonyl benzaldehyde are added to obtain a ring compound II; the ring compound II is subjected to an isomerization reaction in the alcohols solvent to obtain (4R,5R)-2-bischloromethyl-4,5-dihydro-5-(4-methylsulfonyl)-4-oxazole methyl alcohol. According to the method, a brand-new synthetic route is adopted, and generation of a large amount of copper-containing wastewater difficult to treat is avoided; hydrogen is adopted for reduction, generation of a large number of three wastes is avoided, cost is reduced, the total yield is high and is over 98%, benefits are increased, and environment is protected.