Phosphinic Acid → (S)-5-tert-Butyl 6-methyl 5-azaspiro[2.4]heptane-5,6-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To the solution of (6S)-5-tert-butyl 6-methyl 1,1-dibromo-5-azaspiro[2.4]heptane-5,6-dicarboxylate (69 mg, 0.167 mmol) in water (1 mL) and ACN (0.5 mL) were added the hypophosphorous acid (0.078 mL, 0.96 mmol), TEA (0.27 mL, 1.92 mmol) and V-50 (4.5 mg, 0.0167 mmol). The solution was degassed and was heated at 90° C. for 15 hours. After being cooled, the solution was diluted with H2O, extracted with EtOAc (×3) and was dried (Na2SO4), concentrated. The crude product was treated under the conditions above for another 15 hours. After cooled, the solution was diluted with H2O (10 mL) and tuned to pH 4 by adding aq HCl (4 N). The aqueous phase was extracted with EtOAc (×3), dried (Na2SO4). After concentrated under vacuum, the title compound was obtained as colorless oil (20 mg, 42%).

Provenance & Evidence