1: 87 percent / triethylamine / CH2Cl2 / 0.5 h / Ambient temperature 2: dimethylformamide / -15 °C View Scheme

1: 81 percent / xylene / 3 h / Heating 2: 1.) BF3*Et2O, NaBH4, 2.) NaF, 6 N HCl / 1.) diglycol dimethyl ether, 2 h, 70 deg C, 2.) diglycol dimethyl ether, 30 min, 100 deg C 3: 87 percent / triethylamine / CH2Cl2 / 0.5 h / Ambient temperature 4: dimethylformamide / -15 °C View Scheme

1: 1.) BF3*Et2O, NaBH4, 2.) NaF, 6 N HCl / 1.) diglycol dimethyl ether, 2 h, 70 deg C, 2.) diglycol dimethyl ether, 30 min, 100 deg C 2: 87 percent / triethylamine / CH2Cl2 / 0.5 h / Ambient temperature 3: dimethylformamide / -15 °C View Scheme

in N,N-dimethyl-formamide T=-15°C;

methanol in dichloromethane (N2), dissolved compounds mixed, stirred for 2 h; volume reduced, CH2Cl2 removed, CH3OH added, precipitated with Et2O, centrifuged, washed with Et2O, dried in vac.; elem. anal.;