3-Cyclohexyl-L-alanine → (S)-a-Hydroxy-cyclohexanepropanoic acid

Participants

Reaction Steps

To a stirring suspension of L-cyclohexylalanine (4.00 g,23.4 mmol) in 0.5M H2SO4 (120 mL) at 0° C. was slowly added dropwise an aqueous solution of NaNO2 (12.1 g in 40 mL H2O). Addition was complete after approximately 1 h, at which point the solution was allowed to warm to room temperature. After 16 h, the reaction mixture was extracted with ether (3×100 mL), and the combined organic extracts were washed with 1M NaHSO4 (1×200 mL) and brine (1×100 mL) and then dried over anhydrous Na2SO4. The solvent was removed in vacuo, and the crude product was recrystallized from Et2O/pentane (10 mL/100 mL) to afford 2.1 g (52% yield) of (S)-2-hydroxy-3-cyclohexylpropionic acid as fine white needles.

Provenance & Evidence