1.1: 2-cyanoethyl N,N,N',N'-tetra-isopropylphosphorodiamidite / dichloromethane / 2 h / 20 °C / Inert atmosphere; Molecular sieve 1.2: 1.5 h / 20 °C 1.3: 0.17 h / 0 - 20 °C 2.1: Pearlman's catalist; hydrogen; acetic acid / methanol / 7 h / 20 °C / 760.05 Torr View Scheme

1: With triethylamine in dichloromethane; acetonitrile 2: With tetrabutyl ammonium fluoride in tetrahydrofuran T=45°C; 2 h;

1.1: POCl3; ethyl N,N-diisopropylamine / CHCl3 / 2 h / 0 °C 1.2: 53 percent / pyridine / CHCl3 / 0 - 20 °C 2.1: 65 percent / palmitic acid / dimethylformamide / 26 h / 80 °C View Scheme

1: pyridine / CHCl3 / Ambient temperature 2: 10percent aq. NaHCO3 / CHCl3 / Ambient temperature View Scheme

1: POCl3 2: H2 / Pd(OH)2 View Scheme

pyridine; trichloroacetonitrile T=50°C; 48 h; Yield given;

pyridine; NaBO3; dimethylsulfide borane complex; triethylamine; trichlorophosphate 2.) CHCl3, 3.) CHCl3, -20 deg C; Yield given. Multistep reaction;

1: 2-O-hexadecanoyl-1-O-hexadecyl-sn-glycerol With triethylamine; trichlorophosphate in dichloromethane T=20°C; 0.5 h; 2: choline p-toluenesulfonate With pyridine in dichloromethane T=20°C; 16 h;

1: (4S)-4-[(1R)-1-(tert-butyldiphenylsilyloxy)-hexadec-2-enyl]-2-chloro-2-oxo-[1,3,2]-oxazaphospholidine; choline p-toluenesulfonate With triethylamine in dichloromethane; acetonitrile T=20°C; 12 h; 2: With hydrogenchloride; water in tetrahydrofuran 3: n-hexadecanoyl chloride With tetrabutyl ammonium fluoride more than 3 stages;