(S)-3-(4-acetylamino-2-benzyloxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester → (S)-3-(4-acetylamino-2-hydroxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester

Participants

Reaction Steps

11.4 g (20.7 mmol) (S)-3-(4-Acetylamino-2-benzyloxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester, 1 g 20% Pd/C, and 100 mL tetrahydrofuran was shaken under a 50 psi hydrogen atmosphere for 19 h. TLC analysis indicated incomplete reaction, so an additional 1 g 20% Pd/C was added and the reaction shaken an additional 20 h under a 50 psig hydrogen atmosphere. TLC showed complete reaction. The catalyst was filtered and the resulting solution was concentrated to give an oil. The product was purified over silica eluting with ethyl acetate to yield 9.37 g (20.34 mmol, 98.3%) of (S)-3-(4-acetylamino-2-hydroxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester as an ivory-yellow solid. MS (APCI) m/z 459.1 (M−1).

Provenance & Evidence