1: With n-butyllithium; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran; hexane T=-78°C; 1 h; 2: With boric acid trimethyl ester in tetrahydrofuran; hexane T=-78°C; 1.5 h; 3: With hydrogenchloride in tetrahydrofuran; hexane T=20°C; Further stages.;

1.1: n-butyllithium; N,N,N',N'-tetramethylethylenediamine / tetrahydrofuran 1.2: 95 percent / 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone / tetrahydrofuran 2.1: n-butyllithium; N,N,N',N'-tetramethylethylenediamine / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: trimethyl borate / tetrahydrofuran; hexane / 1.5 h / -78 °C 2.3: 61 percent / aq. HCl / tetrahydrofuran; hexane / 20 °C View Scheme

1.1: 46.3 g / H2 / PtO2 / pentane / 12 h / 760 Torr 2.1: n-BuLi / tetrahydrofuran / 0.25 h / -78 °C 2.2: tetrahydrofuran / -78 - 20 °C 3.1: aq. HCl / diethyl ether View Scheme

1.1: P2O5 / pentane 2.1: 46.3 g / H2 / PtO2 / pentane / 12 h / 760 Torr 3.1: n-BuLi / tetrahydrofuran / 0.25 h / -78 °C 3.2: tetrahydrofuran / -78 - 20 °C 4.1: aq. HCl / diethyl ether View Scheme