1-bromoundeca-2,5-diyne

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 1 L three-necked, flame-dried round bottom flask fitted with a reflux condenser and a rubber septum was placed 3.86 g (159 mmol) of magnesium in 250 mL of anhydrous tetrahydrofuran. Bromoethane (17.3 g; 1586 mmol) in 250 mL anhydrous tetrahydrofuran was added dropwise, under argon, and the reflux rate was controlled with the aid of an ice-water bath. The mixture was heated to reflux and stirred for 1 hour. 3-Butyn-1-ol (5.56 g, 79.3 mmol), dissolved in 150 mL of anhydrous tetrahydrofuran, was slowly added dropwise with stirring (2 hours). Following addition, the reaction was heated to reflux. After stirring for 90 minutes, 0.5 g (2.63 mmol) of cuprous (I) iodide was added. After 75 minutes 9.0 g (39.65 mmol) of 1-bromo-2,5-undecadiyne dissolved in 150 mL of anhydrous tetrahydrofuran was added. The mixture was heated at reflux for 12 h and an additional 0.25 g (1.32 mmol) of cuprous (I) iodide was added. The mixture was heated at reflux for 7 hours, cooled and quenched by addition of 400 mL of ice-water saturated with ammonium chloride. After filtration (Celite), the filtrate was extracted with 3×400 mL of ether. The ether layers were washed with 2×300 mL of saturated ammonium chloride solution, 3×200 mL of water, 250 mL of brine, dried (Na2SO4), and concentrated in vacuo to yield 6.2 g of yellow-brown oil. The residue was partially purified by crystallization (petroleum ether) at -20° C. to produce 5.75 g (75%) of an unstable yellow oil (room temperature) which was utilized immediately in the next reaction. IR (neat,cm-1) 3365, 2956, 2933, 2225; 1H NMR (CDCl3) δ 3.70 (t, J=6.2 Hz, 2H), 3.17-3.13 (m, 4H), 2.45 (dt, J=1.5, 5.9, 12.0 Hz, 2H), 2.15 (dt, J=2.1, 6.9, 13.9 Hz, 2H), 1.68 (br, 1H), 1.55-1.43 (m, 2H), 1.43-1.26 (m, 4H), 0.89 (t, J=6.9 Hz, 3H); HRMS calculated for C15H20O (M+) 216.1514, found 216.1519. In a 1 L three-necked, flame-dried round bottom flask fitted with a reflux condenser the reflux rate was controlled with the aid of an ice-water bath The mixture was heated to reflux was slowly added dropwise with stirring (2 hours) addition the reaction was heated to reflux After stirring for 90 minutes was added The mixture was heated at reflux for 12 h The mixture was heated at reflux for 7 hours cooled quenched by addition of 400 mL of ice-water saturated with ammonium chloride After filtration (Celite) the filtrate was extracted with 3×400 mL of ether The ether layers were washed with 2×300 mL of saturated ammonium chloride solution, 3×200 mL of water, 250 mL of brine dried (Na2SO4) concentrated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 1 L three-necked, flame-dried round. bottom flask fitted with a reflux condenser and a rubber septum was placed 3.86 g (159 mmol) of magnesium in 250 mL of anhydrous tetrahydrofuran. Bromoethane (17.3 g; 1586 mmol) in 250 mL anhydrous tetrahydrofuran was added dropwise, under argon, and the reflux rate was controlled with the aid of an ice-water bath. The mixture was heated to reflux and stirred for 1 hour. 3-Butyn-1-ol (5.56 g, 79.3 mmol), dissolved in 150 mL of anhydrous tetrahydrofuran, was slowly added dropwise with stirring (2 hours). Following addition, the reaction was heated to reflux. After stirring for 90 minutes, 0.5 g (2.63 mmol) of cuprous (I) iodide was added. After 75 minutes 9.0 g (39.65 mmol) of 1-bromo-2,5-undecadiyne dissolved in 150 mL of anhydrous tetrahydrofuran was added. The mixture was heated at reflux for 12 h and an additional 0.25 g (1.32 mmol) of cuprous (I) iodide was added. The mixture was heated at reflux for 7 hours, cooled and quenched by addition of 400 mL of ice-water saturated with ammonium chloride. After filtration (Celite), the filtrate was extracted with 3×400 mL of ether. The ether layers were washed with 2×300 mL of saturated ammonium chloride solution, 3×200 mL of water, 250 mL of brine, dried (Na2SO4), and concentrated in vacuo to yield 6.2 g of yellow-brown oil. The residue was partially purified by crystallization (petroleum ether) at -20° C. to produce 5.75 g (75%) of an unstable yellow oil (room temperature) which was utilized immediately in the next reaction. IR (neat, cm-1) 3365, 2956, 2933, 2225; 1H NMR (CDCl3) δ 3.70 (t, J=6.2 Hz, 2H), 3.17-3.13 (m, 4H), 2.45 (dt, J=1.5, 5.9, 12.0 Hz, 2H), 2.15 (dt, J=2.1, 6.9, 13.9 Hz, 2H), 1.68 (br, 1H), 1.55-1.43 (m, 2H), 1.43-1.26 (m, 4H), 0.89 (t, J=6.9 Hz, 3H); HRMS calculated for C15H20O (M+) 216.1514, found 216.1519. In a 1 L three-necked, flame-dried round bottom flask fitted with a reflux condenser the reflux rate was controlled with the aid of an ice-water bath The mixture was heated to reflux was slowly added dropwise with stirring (2 hours) addition the reaction was heated to reflux After stirring for 90 minutes was added The mixture was heated at reflux for 12 h The mixture was heated at reflux for 7 hours cooled quenched by addition of 400 mL of ice-water saturated with ammonium chloride After filtration (Celite) the filtrate was extracted with 3×400 mL of ether The ether layers were washed with 2×300 mL of saturated ammonium chloride solution, 3×200 mL of water, 250 mL of brine dried (Na2SO4) concentrated in vacuo