Methanol → (2R)-2-cyclohexyl-2-hydroxyacetic acid

HRID 2105762Notes

Reaction equation

HRID 2105762 reaction equation
CO.[CH:3]1[CH:8]=[CH:7][C:6]([C@@H:9]([OH:13])[C:10]([OH:12])=[O:11])=[CH:5][CH:4]=1>[Rh].C(O)(=O)C>[CH:6]1([C@@H:9]([OH:13])[C:10]([OH:12])=[O:11])[CH2:7][CH2:8][CH2:3][CH2:4][CH2:5]1

Participants

5

Reactant 2

HCID 887MethanolHCID 11914(-)-Mandelic acid

Product 1

HCID 819914(2R)-2-cyclohexyl-2-hydroxyacetic acidYield 92%

Reagents, catalysts & solvents 2

HCID 23948RhodiumCatalystHCID 176Acetic AcidSolvent

Procedure

To a solution of 200 mL methanol were added 38.0 g of R-(−)-mandelic acid, 2.5 mL acetic acid, and 7.5 g rhodium on carbon (5%, Engelhard 5864). The mixture was sealed in an autoclave, purged with nitrogen, and then filled with hydrogen gas. Hydrogenation was carried out at room temperature for 8 hours at 1400 psi. The reaction mixture was then removed from the autoclave and filtered. The filtrate was concentrated and recrystallized from toluene. The colorless crystals were collected by filtration and dried under vacuum to give 19.8 g of (R)-(−)-2-cyclohexyl-2-hydroxyacetic acid (92.0% yield from 20.7 g R-(−)-mandelic acid). 1H NMR (DMSO-d6): δ (ppm) 3.71 (d, 1H), 1.69-1.52 (m, 6H), 1.16-1.09 (m, 5H). 13C NMR (DMSO-d6): δ (ppm) 175.27, 74.19, 41.15, 28.86, 26.74, 25.84, 25.76, 25.57. IR (KBr): ν (cm−1) 3442, 2935, 2854, 1716, 1452, 1280, 1261, 1232, 1112, 1099. Anal. Calcd. for C8H14O3: C, 60.74; H, 8.92. Found: C, 60.89; H, 8.90. mp 124-126° C. [α]D20=−12.0° (c=1.0, CH3OH)

Workup

  1. customThe mixture was sealed in an autoclave
  2. custompurged with nitrogen
  3. additionfilled with hydrogen gas
  4. customThe reaction mixture was then removed from the autoclave
  5. filtrationfiltered
  6. concentrationThe filtrate was concentrated
  7. customrecrystallized from toluene
  8. filtrationThe colorless crystals were collected by filtration
  9. customdried under vacuum

Sources & evidence

ORD record
ord-58f5d6efeb0f4c4682a4a90ff5e32308
Source dataset
uspto-grants-2009_08
Patent number
US07579429B2

Reaction notes

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