ChemicalBook CAS DataBase List Methyl (R)-(+)-lactate

Methyl (R)-(+)-lactate synthesis

10synthesis methods

Product Name:Methyl (R)-(+)-lactate
CAS Number:17392-83-5
Molecular formula:C4H8O3
Molecular Weight:104.1

600-22-6 Synthesis

600-22-6
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$6.00/5g

17392-83-5
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$6.00/25g

Yield: 88.2 % ee

Reaction Conditions:

Stage #1:bis(1,5-cyclooctadiene)rhodium(I) trifluoromethanesulfonate;(R)-N-diphenylphosphino-N-methyl-[(S)-2-(diphenylphosphino)ferrocenyl]ethylamine in tetrahydrofuran at 25; for 0.25 h;
Stage #2:pyruvic acid methyl ester with hydrogen in tetrahydrofuran under 1277.21 - 1794.37 Torr; for 6 h;Product distribution / selectivity;

Steps:

18 Methyl Lactate using the Rhodium Complex of Ligand 4a
Methyl pyruvate (51 mg; 0.50 mmol) was dissolved in a reaction vessel in anhydrous THF (3.0 mL) and degassed with argon for 15 minutes. Bis(1,5-cycloocta-diene)rhodium trifluoromethanesulfonate (2.3 mg; 5 μmol; 0.01 equiv) and ligand 4a from Example 1 (3.7 mg; 6 μmol; 0.012 equiv) were combined and argon-degassed anhydrous THF (2.0 mL) was added. This solution was stirred at 25° C. under argon for 15 minutes and then added to the solution of 2-acetamidocinnamic acid. The resulting solution was then flushed with hydrogen and pressurized to 0.69-1.38 bars gauge (10-20 psig) hydrogen. The reaction mixture was stirred for 8 hours to afford 90.2% conversion to methyl (R)-lactate with 88.2% ee as determined by chiral GC analysis. The analytical properties of methyl lactate were identical to an authentic sample.Chiral GC [Cyclosil-B (J&W Scientific) 30 m×0.25 mm ID, film thickness 0.25 μm, 75° C. isothermal, 15 psig He]: t_R[methyl (R)-lactate] 7.75 min, t_R[methyl (S)-lactate] 9.16 min. t_R(methyl pyruvate) 5.16 min.

References:

Eastman Chemical Company US6906213, 2005, B1 Location in patent:Page/Page column 15

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