potassium carbonate in methanol 19 h; Ambient temperature; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

potassium carbonate 19 h; Ambient temperature; Yields of byproduct given;

1: With N,N,N',N'-tetramethylguanidine in tetrahydrofuran T=25°C; 72 h; 2: With silica gel in tetrahydrofuran; chloroform T=20°C; 72 h; Title compound not separated from byproducts;

1: 1.) (nBu)2BOTf, Et3N, 4.) H2O2 / 1.) -78 deg C, 30 min, 2.) 20 deg C, 2 h, 3.) 0 deg C, 2 h, 4.) MeOH, ether, 0 deg C, 1 h 2: 92 percent / NaN3 / dimethylsulfoxide / 12 h / 25 °C 3: 97 percent / 2,6-lutidine / CH2Cl2 / 2.5 h / 0 °C 4: 81 percent / LiBH4 / tetrahydrofuran / 3 h / 0 °C 5: 90 percent / nBu4NF / tetrahydrofuran / 1 h / 25 °C 6: HS(CH2)3SH, Et3N / methanol / 24 h / 25 °C View Scheme

in dimethyl sulfoxide

ozone in acetonitrile 0.166667 h;

1: 1.) (nBu)2BOTf, Et3N, 4.) H2O2 / 1.) -78 deg C, 30 min, 2.) 20 deg C, 2 h, 3.) 0 deg C, 2 h, 4.) MeOH, ether, 0 deg C, 1 h 2: 92 percent / NaN3 / dimethylsulfoxide / 12 h / 25 °C 3: 97 percent / 2,6-lutidine / CH2Cl2 / 2.5 h / 0 °C 4: 81 percent / LiBH4 / tetrahydrofuran / 3 h / 0 °C 5: 90 percent / nBu4NF / tetrahydrofuran / 1 h / 25 °C View Scheme

1: LiHMDS; CsF / tetrahydrofuran / 2 h / 0 °C 2: 86 percent / LiHMDS / tetrahydrofuran / 2.5 h / -78 - -45 °C 3: 62 percent / TMSCl; LDA / tetrahydrofuran; cyclohexane / 0.25 h / -95 °C View Scheme