2-methyl-1,3-dithiane

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Methyl-1,3-dithiane (1.50 g, 11.2 mmol) was dissolved in THF (50 mL), followed by cooling to −20° C. Then, n-butyllithium (1.58 M solution in hexane, 7 mL, 11.1 mmol) was added dropwise and the mixture was stirred for two hours. Ethyl trifluoroacetate (1.4 mL, 11.8 mmol) was added, and the mixture was heated to room temperature and stirred for 20 hours. Aqueous ammonium chloride solution was added to the reaction solution, followed by extraction with ethyl acetate. Then, the organic layer was washed with brine and dried over anhydrous sodium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15) to obtain 1.09 g of the title compound as a pale yellow solid (42%). the mixture was heated to room temperature stirred for 20 hours followed by extraction with ethyl acetate Then, the organic layer was washed with brine dried over anhydrous sodium sulfate concentration under reduced pressure the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15)

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:-30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 56 mmol of n-butyllithium (35 ml of a 1.6 M solution in hexane) were added with stirring to a solution of 2-methyl-1,3-dithian (7 g, 52.1 mmol) in 100 ml of dry tetrahydrofuran at −30° C. under argon. After stirring at −30° C. for 2 hours, the mixture was cooled to −78° C. 4.2 g (58.3 mmol) of freshly distilled n-butyraldehyde were added dropwise in the course of 15 minutes and the mixture was stirred for a further 30 minutes. After warming to 20° C., it was poured into a beaker containing 300 ml of water and 100 ml of n-hexane. The organic phase was separated off and the aqueous phase was extracted three times with 50 ml of dichloromethane in each case. The combined organic phases were washed with 10% strength by weight potassium hydroxide solution, water and concentrated sodium chloride solution, dried over anhydrous sodium sulfate and then distilled. 8.82 g of 2-(1-hydroxybutyl)-2-methyl-1,3-dithian were isolated as a colorless oil. the mixture was cooled to −78° C the mixture was stirred for a further 30 minutes After warming to 20° C. it was poured into a beaker The organic phase was separated off the aqueous phase was extracted three times with 50 ml of dichloromethane in each case The combined organic phases were washed with 10% strength by weight potassium hydroxide solution, water and concentrated sodium chloride solution dried over anhydrous sodium sulfate distilled

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Methyl-1,3-dithiane (1.50 g, 11.2 mmol) was dissolved in THF (50 mL), followed by cooling to −20° C. Then, n-butyllithium (1.58 M solution in hexane, 7 mL, 11.1 mmol) was added dropwise and the mixture was stirred for two hours. Ethyl trifluoroacetate (1.4 mL, 11.8 mmol) was added, and the mixture was heated to room temperature and stirred for 20 hours. Aqueous ammonium chloride solution was added to the reaction solution, followed by extraction with ethyl acetate. Then, the organic layer was washed with brine and dried over anhydrous sodium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15) to obtain 1.09 g of the title compound as a pale yellow solid (42%). the mixture was heated to room temperature stirred for 20 hours followed by extraction with ethyl acetate Then, the organic layer was washed with brine dried over anhydrous sodium sulfate concentration under reduced pressure the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15)

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Methyl-1,3-dithiane (1.50 g, 11.2 mmol) was dissolved in THF (50 mL), followed by cooling to −20° C. Then, n-butyllithium (1.58 M solution in hexane, 7 mL, 11.1 mmol) was added dropwise and the mixture was stirred for two hours. Ethyl trifluoroacetate (1.4 mL, 11.8 mmol) was added, and the mixture was heated to room temperature and stirred for 20 hours. Aqueous ammonium chloride solution was added to the reaction solution, followed by extraction with ethyl acetate. Then, the organic layer was washed with brine and dried over anhydrous sodium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15) to obtain 1.09 g of the title compound as a pale yellow solid (42%). the mixture was heated to room temperature stirred for 20 hours followed by extraction with ethyl acetate Then, the organic layer was washed with brine dried over anhydrous sodium sulfate concentration under reduced pressure the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15)

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

Procedure: n-Butyllithium (1.5M in hexane, 12 ml) was added over 5 min to a stirred solution of 2-methyl-1,3-dithiane (2.4 g) in dry THF (30 ml) at 70° under nitrogen. The yellow solution was then stirred at -30° to -20° for 2 h, cooled to -78° and treated with a solution of the product of stage (iii) (6.1 g) in THF (25 ml). The solution was stirred at room temperature overnight, the solvent was evaporated and the residue was purified by FCC (hexane→System D 9:1) to give the title compound as a pale yellow oil (3.2 g) T.l.c. (System D 9:1) Rf 0.18. cooled to -78° The solution was stirred at room temperature overnight the solvent was evaporated the residue was purified by FCC (hexane→System D 9:1)

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Methyl-1,3-dithiane (1.50 g, 11.2 mmol) was dissolved in THF (50 mL), followed by cooling to −20° C. Then, n-butyllithium (1.58 M solution in hexane, 7 mL, 11.1 mmol) was added dropwise and the mixture was stirred for two hours. Ethyl trifluoroacetate (1.4 mL, 11.8 mmol) was added, and the mixture was heated to room temperature and stirred for 20 hours. Aqueous ammonium chloride solution was added to the reaction solution, followed by extraction with ethyl acetate. Then, the organic layer was washed with brine and dried over anhydrous sodium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15) to obtain 1.09 g of the title compound as a pale yellow solid (42%). the mixture was heated to room temperature stirred for 20 hours followed by extraction with ethyl acetate Then, the organic layer was washed with brine dried over anhydrous sodium sulfate concentration under reduced pressure the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=100/0, 95/5, 85/15)

Conditions: temp:-30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 56 mmol of n-butyllithium (35 ml of a 1.6 M solution in hexane) were added with stirring to a solution of 2-methyl-1,3-dithian (7 g, 52.1 mmol) in 100 ml of dry tetrahydrofuran at −30° C. under argon. After stirring at −30° C. for 2 hours, the mixture was cooled to −78° C. 4.2 g (58.3 mmol) of freshly distilled n-butyraldehyde were added dropwise in the course of 15 minutes and the mixture was stirred for a further 30 minutes. After warming to 20° C., it was poured into a beaker containing 300 ml of water and 100 ml of n-hexane. The organic phase was separated off and the aqueous phase was extracted three times with 50 ml of dichloromethane in each case. The combined organic phases were washed with 10% strength by weight potassium hydroxide solution, water and concentrated sodium chloride solution, dried over anhydrous sodium sulfate and then distilled. 8.82 g of 2-(1-hydroxybutyl)-2-methyl-1,3-dithian were isolated as a colorless oil. the mixture was cooled to −78° C the mixture was stirred for a further 30 minutes After warming to 20° C. it was poured into a beaker The organic phase was separated off the aqueous phase was extracted three times with 50 ml of dichloromethane in each case The combined organic phases were washed with 10% strength by weight potassium hydroxide solution, water and concentrated sodium chloride solution dried over anhydrous sodium sulfate distilled