Reaction #1121749

Reaction equation

NaOH

NaOH

methanol

5-methyl-3-nitromethyl-hexanoic acid ethyl ester

(S)-5-methyl-3-nitromethyl-hexanoic acid ethyl ester

→

title compound

(S)-5-methyl-3-nitromethyl-hexanoic acid sodium salt

Solvents

potassium phosphate

Conditions

Workup

1. 1
   OtherAfter 45% conversion (corresponding to 4.0 mL of 0.1M NaOH consumption) the reaction
2. 2
   workup.ADDITIONwas stopped by addition of 10 mL of ethyl acetate
3. 3
   OtherThe layers were separated
4. 4
   Extractionthe aqueous layer was extracted once more with 10 mL of ethyl acetate
5. 5
   ConcentrationThen the aqueous layer was concentrated

Procedure

In a beaker 100 mg of EstC (lyophilized) were dissolved/suspended in 10 mL of potassium phosphate buffer (1 mM, pH 7.2). The pH drops to pH ˜6.8 and was adjusted to pH=7.4 with aqueous NaOH (0.1 M). Then 250 μL of methanol and 200 mg of 5-methyl-3-nitromethyl-hexanoic acid ethyl ester (VIII, R1=ethyl) were added and the pH was kept at 7.4 by continuous addition of aqueous NaOH (0.1M). After 45% conversion (corresponding to 4.0 mL of 0.1M NaOH consumption) the reaction was stopped by addition of 10 mL of ethyl acetate. The layers were separated and the aqueous layer was extracted once more with 10 mL of ethyl acetate. Then the aqueous layer was concentrated to give the title compound with an ee of 98%.

Source