General Description
Methyl (R)-(-)-3-hydroxybutyrate is a monocarboxylic acid that
is metabolized by phosphofructokinase and other enzymes to produce the
corresponding 3-hydroxybutyrate. This compound is synthesized from
tiglic acid, which can be obtained from corynebacterium. The production
of it can be optimized by using a
biotransformation process.
Synthesis
In the glove box, put RuCl3 (0.69mg, 0.0033mmol), (R)-BINAP (2.3mg, 0.0036mmol), (1R,2R)-1,2-diphenyl-1,2-ethylenediamine (0.78 mg, 0.0036mmol) and isopropanol (150g) were added to a single-necked flask equipped with a magnetic stirrer, the stirring was turned on, the metal precursor and the ligand were dissolved and coordinated for 30 minutes,Obtain the catalyst solution, seal the single-neck bottle, take it out of the glove box, and pump it into a 0.5L reactor with a flat flow pump under the protection of nitrogen. The reactor has been replaced with nitrogen in advance, and the substrate methyl acetoacetate (116g, 1mol) and Potassium tert-butoxide (0.12g).After the catalyst solution was added, the reactor was replaced with hydrogen for three times, 8MPa hydrogen was charged, and the reactor was turned on for stirring and heating.When the internal temperature of the reactor reaches 100°C, open the hydrogen gas inlet valve, keep the internal pressure of the reactor at 10MPa, start timing, keep the reaction for 5 hours, the flowmeter shows that the hydrogen absorption rate is less than 0.1mL/min, terminate the reaction, and cool the reactor To room temperature, sampling and GC analysis showed that the conversion rate of raw material methyl acetoacetate was 99.9%, and the selectivity of (R)-1,3-butanediol was 8.8%.The ee value is 99.2%, and the selectivity of Methyl (R)-(-)-3-hydroxybutyrate is 90.9%.
