1.1: n-butyllithium; diisopropylamine / tetrahydrofuran; hexane / 0.25 h / -78 °C / Inert atmosphere 1.2: 3.17 h / -78 - 20 °C / Inert atmosphere 2.1: copper(l) iodide / tetrahydrofuran; diethyl ether / 0.08 h / 0 °C / Inert atmosphere 2.2: 1 h / -78 °C / Inert atmosphere 3.1: lithium aluminium tetrahydride / diethyl ether / 1 h / Inert atmosphere View Scheme

ammonium chloride in tetrahydrofuran; methanol; water To a stirred soln. of Me3SnCu*Me2S in THF (Ar, -78°C) was added sequentially a THF soln. of the 1-alkyne and CH3OH. The mixt. was stirred(10 min) and then at -63°C (12 h). Satd. aq. NH4Cl and ether were added; allowed to warm to room temp.; Aq. phase was extd. (ether). The org. exts. were washed (satd. aq. NH4Cl) and dried (MgSO4). Removal of the solvent; column chromy. (silica gel) followed by distn. (12 Torr). (E)-1-trimethylstannyl-1-alkene not isolated, detected by gas-liq. chromy..;

methanol in tetrahydrofuran molar ratio Sn:alkyne:MeOH=1:2:60; chromy. (SiO2, light petroleum);

n-butyllithium in tetrahydrofuran T=-78 - 20°C; 4 h;

1: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; Inert atmosphere; 2: With formaldehyd in tetrahydrofuran; hexane T=-78 - 20°C; 4 h; Inert atmosphere;

N-bromosuccinmide; silver nitrate in acetone 1.25 h;

1: 84 percent / N-bromosuccinimide; silver nitrate / acetone 2: KMnO4; NaHCO3; MgSO4 / acetone; H2O / 0 °C 3: diethyl ether / 0 °C View Scheme

1: 1-(t-butyldimethylsilyloxy)-3-butyne With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1 h; 2: N-Methoxy-N-methyl-benzamide in tetrahydrofuran; hexane T=-78 - 20°C; 2 h; Further stages.;

bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine T=20°C; Sonogashira coupling;