ethyl 3-bromo-2-(bromomethyl)propanoate

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

Procedure: A mixture of triethylamine (10.1 ml, 72 mmol) and 3,6-dihydro-4-(1-pyrrolidinyl)-2H-thiopyran (12.9 g, 76 mmol, prepared according to a procedure described in Tetrahedron Asymmetry 1997, 1811-1820) in anhydrous acetonitrile (55 ml) was heated to reflux, then ethyl 3-bromo-2-(bromomethyl)propionate (14.6 g, 53 mmol) in dry acetonitrile (42 ml) was added dropwise over a period of 45 min. The resulting reaction mixture was refluxed for another 1.5 hours, then cooled to room temperature before a 10% aqueous acetic acid solution (5.2 ml) was added. The mixture was then refluxed for 1 hour and evaporated to dryness. Brine was added to the residue, the aqueous phase was extracted with ethyl acetate, the combined organic extracts were dried over anhydrous sodium sulphate, filtered and concentrated in vacuo to yield 9-oxo-3-thia-bicyclo[3.3.1]nonane-7-carboxylic acid ethyl ester as a brown oil (15.5 g). prepared was heated to reflux The resulting reaction mixture was refluxed for another 1.5 hours was added The mixture was then refluxed for 1 hour evaporated to dryness Brine was added to the residue the aqueous phase was extracted with ethyl acetate the combined organic extracts were dried over anhydrous sodium sulphate filtered concentrated in vacuo

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

Procedure: 3-Bromo-2-bromomethyl-propionic acid ethyl ester (5.48 g, 20 mmol) was added to a mixture of 1-cyclopent-1-enyl-pyrrolidine (2.74 g, 20 mmol) and Hünig's base (3.5 mL) in MeCN (15 mL) with vigorous stirring. An exothermic reaction ensued, bringing the mixture to reflux. The mixture was refluxed for 16 h, cooled, and poured into 100 mL of EtOAc with stirring. The resulting solid (3.33 g) was collected by filtration, dissolved in 0.5 M aqueous HCl (100 mL) and stirred with EtOAc (100 mL) for 48 h. The organic layer was separated and concentrated to give 8-oxo-bicyclo[3.2.1]octane-endo-3-carboxylic acid ethyl ester (1.0 g, 5.1 mmol) as a colourless oil. This was dissolved in EtOH (50 mL),treated with a solution of hydroxylamine hydrochloride (1.04 g, 15 mmol) and sodium acetate trihydrate (2.04 g, 15 mmol) in water (10 mL) and heated at reflux for 16 h. The solution was cooled, concentrated, diluted with water (100 mL) and extracted with DCM. The DCM extracts were dried (MgSO4), concentrated and purified by flash chromatography (20→30% EtOAc/hexane) to give the oxime (270 mg) as a colourless oil. 1H NMR (CDCl3, 360 MHz) δ 9.85 (1 H, bs, N—OH), 4.20 (2 H, q, J=7.1 Hz, CH2—O), 3.36 (1 H, bs, bridgehead H), 2.63-2.56 (4 H, m), 2.15-2.04 (2 H, m), 1.76-1.69 (4 H, m), 1.30 (3 H, t, J=7.1 Hz, —Me). m/z 212 (M+H)+. An exothermic reaction to reflux The mixture was refluxed for 16 h cooled The resulting solid (3.33 g) was collected by filtration dissolved in 0.5 M aqueous HCl (100 mL) stirred with EtOAc (100 mL) for 48 h The organic layer was separated concentrated

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

Procedure: 3-Bromo-2-bromomethyl-propionic acid ethyl ester (5.48 g, 20 mmol) was added to a mixture of 1-cyclopent-1-enyl-pyrrolidine (2.74 g, 20 mmol) and Hünig's base (3.5 mL) in MeCN (15 mL) with vigorous stirring. An exothermic reaction ensued, bringing the mixture to reflux. The mixture was refluxed for 16 h, cooled, and poured into 100 mL of EtOAc with stirring. The resulting solid (3.33 g) was collected by filtration, dissolved in 0.5 M aqueous HCl (100 mL) and stirred with EtOAc (100 mL) for 48 h. The organic layer was separated and concentrated to give 8-oxo-bicyclo[3.2.1]octane-endo-3-carboxylic acid ethyl ester (1.0 g, 5.1 mmol) as a colourless oil. This was dissolved in EtOH (50 mL),treated with a solution of hydroxylamine hydrochloride (1.04 g, 15 mmol) and sodium acetate trihydrate (2.04 g, 15 mmol) in water (10 mL) and heated at reflux for 16 h. The solution was cooled, concentrated, diluted with water (100 mL) and extracted with DCM. The DCM extracts were dried (MgSO4), concentrated and purified by flash chromatography (20→30% EtOAc/hexane) to give the oxime (270 mg) as a colourless oil. 1H NMR (CDCl3, 360 MHz) δ 9.85 (1 H, bs, N—OH), 4.20 (2 H, q, J=7.1 Hz, CH2—O), 3.36 (1 H, bs, bridgehead H), 2.63-2.56 (4 H, m), 2.15-2.04 (2 H, m), 1.76-1.69 (4 H, m), 1.30 (3 H, t, J=7.1 Hz, —Me). m/z 212 (M+H)+. An exothermic reaction to reflux The mixture was refluxed for 16 h cooled The resulting solid (3.33 g) was collected by filtration dissolved in 0.5 M aqueous HCl (100 mL) stirred with EtOAc (100 mL) for 48 h The organic layer was separated concentrated

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

Procedure: A mixture of triethylamine (10.1 ml, 72 mmol) and 3,6-dihydro-4-(1-pyrrolidinyl)-2H-thiopyran (12.9 g, 76 mmol, prepared according to a procedure described in Tetrahedron Asymmetry 1997, 1811-1820) in anhydrous acetonitrile (55 ml) was heated to reflux, then ethyl 3-bromo-2-(bromomethyl)propionate (14.6 g, 53 mmol) in dry acetonitrile (42 ml) was added dropwise over a period of 45 min. The resulting reaction mixture was refluxed for another 1.5 hours, then cooled to room temperature before a 10% aqueous acetic acid solution (5.2 ml) was added. The mixture was then refluxed for 1 hour and evaporated to dryness. Brine was added to the residue, the aqueous phase was extracted with ethyl acetate, the combined organic extracts were dried over anhydrous sodium sulphate, filtered and concentrated in vacuo to yield 9-oxo-3-thia-bicyclo[3.3.1]nonane-7-carboxylic acid ethyl ester as a brown oil (15.5 g). prepared was heated to reflux The resulting reaction mixture was refluxed for another 1.5 hours was added The mixture was then refluxed for 1 hour evaporated to dryness Brine was added to the residue the aqueous phase was extracted with ethyl acetate the combined organic extracts were dried over anhydrous sodium sulphate filtered concentrated in vacuo

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

Procedure: A mixture of triethylamine (10.1 ml, 72 mmol) and 3,6-dihydro-4-(1-pyrrolidinyl)-2H-thiopyran (12.9 g, 76 mmol, prepared according to a procedure described in Tetrahedron Asymmetry 1997, 1811-1820) in anhydrous acetonitrile (55 ml) was heated to reflux, then ethyl 3-bromo-2-(bromomethyl)propionate (14.6 g, 53 mmol) in dry acetonitrile (42 ml) was added dropwise over a period of 45 min. The resulting reaction mixture was refluxed for another 1.5 hours, then cooled to room temperature before a 10% aqueous acetic acid solution (5.2 ml) was added. The mixture was then refluxed for 1 hour and evaporated to dryness. Brine was added to the residue, the aqueous phase was extracted with ethyl acetate, the combined organic extracts were dried over anhydrous sodium sulphate, filtered and concentrated in vacuo to yield 9-oxo-3-thia-bicyclo[3.3.1]nonane-7-carboxylic acid ethyl ester as a brown oil (15.5 g). prepared was heated to reflux The resulting reaction mixture was refluxed for another 1.5 hours was added The mixture was then refluxed for 1 hour evaporated to dryness Brine was added to the residue the aqueous phase was extracted with ethyl acetate the combined organic extracts were dried over anhydrous sodium sulphate filtered concentrated in vacuo

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

Procedure: 3-Bromo-2-bromomethyl-propionic acid ethyl ester (5.48 g, 20 mmol) was added to a mixture of 1-cyclopent-1-enyl-pyrrolidine (2.74 g, 20 mmol) and Hünig's base (3.5 mL) in MeCN (15 mL) with vigorous stirring. An exothermic reaction ensued, bringing the mixture to reflux. The mixture was refluxed for 16 h, cooled, and poured into 100 mL of EtOAc with stirring. The resulting solid (3.33 g) was collected by filtration, dissolved in 0.5 M aqueous HCl (100 mL) and stirred with EtOAc (100 mL) for 48 h. The organic layer was separated and concentrated to give 8-oxo-bicyclo[3.2.1]octane-endo-3-carboxylic acid ethyl ester (1.0 g, 5.1 mmol) as a colourless oil. This was dissolved in EtOH (50 mL),treated with a solution of hydroxylamine hydrochloride (1.04 g, 15 mmol) and sodium acetate trihydrate (2.04 g, 15 mmol) in water (10 mL) and heated at reflux for 16 h. The solution was cooled, concentrated, diluted with water (100 mL) and extracted with DCM. The DCM extracts were dried (MgSO4), concentrated and purified by flash chromatography (20→30% EtOAc/hexane) to give the oxime (270 mg) as a colourless oil. 1H NMR (CDCl3, 360 MHz) δ 9.85 (1 H, bs, N—OH), 4.20 (2 H, q, J=7.1 Hz, CH2—O), 3.36 (1 H, bs, bridgehead H), 2.63-2.56 (4 H, m), 2.15-2.04 (2 H, m), 1.76-1.69 (4 H, m), 1.30 (3 H, t, J=7.1 Hz, —Me). m/z 212 (M+H)+. An exothermic reaction to reflux The mixture was refluxed for 16 h cooled The resulting solid (3.33 g) was collected by filtration dissolved in 0.5 M aqueous HCl (100 mL) stirred with EtOAc (100 mL) for 48 h The organic layer was separated concentrated