1: 1.) N-benzyltrimethylammonium hydroxide, O3, O2, 2.) Me2S / 1.) MeOH, 10 min; -78 deg C, 2.) -78 deg C to r.t., overnight 2: 93 percent / NaBH4 / methanol / 0.5 h / -20 °C 3: 92 percent / H2, HCl, H2O / Pd/C / methanol / 1 h View Scheme

1: 93 percent / NaBH4 / methanol / 0.5 h / -20 °C 2: 92 percent / H2, HCl, H2O / Pd/C / methanol / 1 h View Scheme

Cysteine sulfinic acid; glutamic oxaloacetic aminotransferase 1.) water, pH= 7, room temp; 2.) water, 9 h; Yield given. Multistep reaction;