in tetrahydrofuran T=20°C; 18 h;

in tetrahydrofuran byproducts: bis(trimethylsilyl) ether; the aldehyde was added by syringe at -78°C under Ar to a THF soln. of the carbanion, the mixt. was stirred 2-3 h at -78°C and allowed to warm to 25°C overnight; (Z)/(E) isomer ratio ca. 7:3 ((1)H NMR), total yield 73percent; reaction mixt. was treated with cold 2 M HCl, extd. with 5:1 Et2O-CH2Cl2, ext. washed with satd. NaCl, dried over MgSO4 and distilled; elem. anal. for isomer mixt.;

in tetrahydrofuran

oxygen; palladium diacetate T=95°C; 8 h; Product distribution; Further Variations:ReagentsSolventsTemperaturesreaction times;