Method for synthesizing (3R,5S)-6-chloro-3,5-dihydroxyhexanoate

The invention discloses a method for synthesizing (3R,5S)-6-chloro-3,5-dihydroxyhexanoate, wherein the method comprises the following steps: preparing 4-chloro-3-hydroxybutyrate; preparing tert-butyl (S)-6-chloro-5-hydroxy-3-oxo-hexanoate from the 4-chloro-3-hydroxybutyrate; adding proper amount of pure water to a reaction kettle as a solvent and adding hydrophosphate to prepare a pH buffer solution which is 0.05mol/L-0.15mol/L in molar concentration, so as to generate a (3R,5S)-6-chloro-3,5-dihydroxyhexanoate solution with the presence of a biological catalyst and a hydrogen donor, and reacting at 45-55 DEG C for 10-15h; and after reaction, sequentially filtering, extracting, decompressing and concentrating, and rectifying so as to obtain a finished (3R,5S)-6-chloro-3,5-dihydroxyhexanoate product; the mass-volume concentration of the (3R,5S)-6-chloro-3,5-dihydroxyhexanoate is 8g/mL-17g/mL, and the dosage of carboxyl reductase is 4-6% of the (3R,5S)-6-chloro-3,5-dihydroxyhexanoate. The method disclosed by the invention not only is capable of reducing production cost and is conducive to energy conservation and emission reduction, but also is higher in molar yield from a production reaction process.