1: in water T=20°C; pH=7.6; 2 h; Enzymatic reaction; 2: With pyridoxal 5'-phosphate; Escherichia coli branched chain aminotransferase; Escherichia coli aspartate aminotransferase in sodium hydroxide T=20°C; pH=7.6; 15 h; Enzymatic reaction; Further stages.;

1.1: 96 percent / H2SO4 / 12 h / Heating 2.1: LHMDS / tetrahydrofuran / 1 h / -78 °C 2.2: 73 percent / tetrahydrofuran / 2 h / -78 - -30 °C 3.1: 44 percent / 1N NaOH / Pseudomonas mendocina lipase / aq. phosphate buffer / 72 h / 4 °C / pH 7.0 / Enzymatic reaction 4.1: 93 percent / TFA / CH2Cl2; H2O / 2 h / 20 °C / Acid hydrolysis 5.1: 99 percent / LiOH / H2O / pH 10 6.1: 73 percent / pyridoxal phosphate; cysteine sulfinic acid / Glutamic Oxalacetic Transaminase (GOT) / H2O / 24 h / 20 °C / pH 7 / Enzymatic reaction View Scheme

1.1: LHMDS / tetrahydrofuran / 1 h / -78 °C 1.2: 73 percent / tetrahydrofuran / 2 h / -78 - -30 °C 2.1: 44 percent / 1N NaOH / Pseudomonas mendocina lipase / aq. phosphate buffer / 72 h / 4 °C / pH 7.0 / Enzymatic reaction 3.1: 93 percent / TFA / CH2Cl2; H2O / 2 h / 20 °C / Acid hydrolysis 4.1: 99 percent / LiOH / H2O / pH 10 5.1: 73 percent / pyridoxal phosphate; cysteine sulfinic acid / Glutamic Oxalacetic Transaminase (GOT) / H2O / 24 h / 20 °C / pH 7 / Enzymatic reaction View Scheme

1: 99 percent / LiOH / H2O / pH 10 2: 73 percent / pyridoxal phosphate; cysteine sulfinic acid / Glutamic Oxalacetic Transaminase (GOT) / H2O / 24 h / 20 °C / pH 7 / Enzymatic reaction View Scheme

1: 44 percent / 1N NaOH / Pseudomonas mendocina lipase / aq. phosphate buffer / 72 h / 4 °C / pH 7.0 / Enzymatic reaction 2: 93 percent / TFA / CH2Cl2; H2O / 2 h / 20 °C / Acid hydrolysis 3: 99 percent / LiOH / H2O / pH 10 4: 73 percent / pyridoxal phosphate; cysteine sulfinic acid / Glutamic Oxalacetic Transaminase (GOT) / H2O / 24 h / 20 °C / pH 7 / Enzymatic reaction View Scheme

1: 93 percent / TFA / CH2Cl2; H2O / 2 h / 20 °C / Acid hydrolysis 2: 99 percent / LiOH / H2O / pH 10 3: 73 percent / pyridoxal phosphate; cysteine sulfinic acid / Glutamic Oxalacetic Transaminase (GOT) / H2O / 24 h / 20 °C / pH 7 / Enzymatic reaction View Scheme

1.1: SOCl2 / 0 - 20 °C 2.1: DMAP / triethylamine; CH2Cl2 3.1: LiN(SiMe3)2 / tetrahydrofuran / -78 °C 3.2: tetrahydrofuran / -78 °C 4.1: LiOH / H2O; tetrahydrofuran 5.1: TFA / CH2Cl2 View Scheme

1.1: LiN(SiMe3)2 / tetrahydrofuran / -78 °C 1.2: tetrahydrofuran / -78 °C 2.1: LiOH / H2O; tetrahydrofuran 3.1: TFA / CH2Cl2 View Scheme

1.1: LiN(SiMe3)2 / tetrahydrofuran / 0.75 h / -78 °C 1.2: 28 percent / tetrahydrofuran / -78 °C 2.1: LiOH / H2O; tetrahydrofuran 3.1: TFA / CH2Cl2 View Scheme

1: LiOH / H2O; tetrahydrofuran 2: TFA / CH2Cl2 View Scheme