1: 95 percent / glac. AcOH / diethyl ether / 0.5 h / 45 °C 2: 99 percent / Et3N / CHCl3 / 0.02 h / 20 °C 3: 73 percent / UHP / trifluoroacetic acid / 0.17 h / 20 °C 4: UHP / trifluoroacetic acid / 24 h / 20 °C 5: 43 mg / TsCl / acetonitrile; H2O / 24 h / 60 °C View Scheme

Beauveria sulfurescens in dimethyl sulfoxide T=20°C; 48 h;