1: 5 percent Spectr. / acetonitrile / 48 h / 15 °C / Irradiation 2: 71 percent / 4-N,N-dimethylaminopyridine; N,N'-dicyclohexylcarbodiimide / CHCl3 / 24 h / 60 °C 3: 16 percent Spectr. / acetonitrile / 24 h / 15 °C / Irradiation View Scheme

in acetonitrile T=15°C; 48 h; Irradiation; Title compound not separated from byproducts.;

1.1: 5 percent Spectr. / acetonitrile / 48 h / 15 °C / Irradiation 2.1: 71 percent / 4-N,N-dimethylaminopyridine; N,N'-dicyclohexylcarbodiimide / CHCl3 / 24 h / 60 °C 3.1: acetonitrile / 1 h / 15 °C / UV-irradiation 3.2: ethanol; benzene / 1 h 4.1: acetonitrile / 4 h / 15 °C / Irradiation 4.2: 85 percent / ethanol; benzene / 1 h View Scheme