Sodium Hydroxide → (1r,2s,4r)-2-Hydroxy-4-methylcyclohexanecarboxylic acid

Temperatur

50 °C

To a solution of (1R,2S,4R)-2-Hydroxy-4-methyl-cyclohexanecarboxylic acid methyl ester (450 mg, 2.42 mmol) in methanol (12 ml) was added a 2.5 M solution of sodium hydroxide (9.7 ml, 24.2 mmol). The reaction mixture was stirred for 4 h at 50° C. Then, the solvents were removed and the residue was partitioned between 20 ml of H2O acidified to pH 4 and 20 ml of EtOAc. The organic layer was separated and the aqueous phase was washed with ethyl acetate (2×20 ml). The combined ethyl acetate layers were dried (Na2SO4) and concentrated to obtain 313 mg (82%) of (1R,2S,4R)-2-Hydroxy-4-methyl-cyclohexanecarboxylic acid. NMR 1H (CDCl3, 400 MHz): 4.34 ppm (s, 1H); 2.43-2.39 ppm (m, 1H); 1.96-1.76 ppm (m, 5H); 1.14-1.08 ppm (m, 1H); 1.02-0.93 ppm (m, 1H); 0.90 ppm (d, 3H).

1. customThen, the solvents were removed
2. customthe residue was partitioned between 20 ml of H2O
3. customThe organic layer was separated
4. washthe aqueous phase was washed with ethyl acetate (2×20 ml)
5. dry with materialThe combined ethyl acetate layers were dried (Na2SO4)
6. concentrationconcentrated

ORD-Eintrag

ord-16d90cc6102148a4b15535667f28a693

Quelldatensatz

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08329924B2