ethyl 2,2-dimethyl-1,3-dioxane-5-carboxylate

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Lithium aluminum hydride (80 g) is stirred in ether (2000 ml) while the product of Example 3 (230 g) in ether (250 ml) is added dropwise. When the addition is complete the mixture is stirred an additional 16 hours. The reaction mixture is decomposed by careful addition of water (80 ml) followed by 15% aqueous sodium hydroxide (80 ml) and additional water (240 ml). The resulting suspension is filtered, the filter cake washed with ethanol and ether and the combined filtrates evaporated to give a residue. Distillation of the residue gives the title product (155 g) (81%) B.P. 75° C. (0.05 mm). is added dropwise When the addition The resulting suspension is filtered the filter cake washed with ethanol and ether the combined filtrates evaporated to give a residue Distillation of the residue

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Lithium aluminum hydride (80 g) is stirred in ether (2000 ml) while the product of Example 3 (230 g) in ether (250 ml) is added dropwise. When the addition is complete the mixture is stirred an additional 16 hours. The reaction mixture is decomposed by careful addition of water (80 ml) followed by 15% aqueous sodium hydroxide (80 ml) and additional water (240 ml). The resulting suspension is filtered, the filter cake washed with ethanol and ether and the combined filtrates evaporated to give a residue. Distillation of the residue gives the title product (155 g) (81%) B.P. 75° C. (0.05 mm). is added dropwise When the addition The resulting suspension is filtered the filter cake washed with ethanol and ether the combined filtrates evaporated to give a residue Distillation of the residue

反応条件: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of the product of Example 2 (65 g) in dimethyl sulfoxide (65 g) is added sodium chloride (1 g). The mixture is stirred while warming at about 180° C., and water is added in small portions while maintaining the temperature between 170° and 180°. Ethanol and water are evolved and are removed by distillation until about 60 ml of liquid has been collected. The mixture is cooled, ether (200 ml) added, and the mixture partitioned with 3 portions of water (50 ml). The organic phase is dried over sodium sulfate and evaporated to a residue. Distillation of the residue gives the title product (25 g) (57%) B.P. 38° (0.01 mm) nD26 1.4400. while maintaining the temperature between 170° and 180° are removed by distillation until about 60 ml of liquid has been collected The mixture is cooled ether (200 ml) added the mixture partitioned with 3 portions of water (50 ml) The organic phase is dried over sodium sulfate evaporated to a residue Distillation of the residue

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of 2,2-dimethyl-[1,3]dioxane-5-carboxylic acid ethyl ester (7.03 g, 37.35 mmol) in tetrahydrofuran (20 ml) was added dropwise to a cooled to 0° C. suspension of lithium aluminum hydride (1.8 g, 48.55 mmol) in tetrahydrofuran (20 ml). The reaction was stirred at 0° C. for 20 min and at 25° C. for 2 h. After such time, ethyl acetate (1 ml) and a few crystals of sodium sulphate decahydrate were added with caution. After stirring at 25° C. for 1 h saturated sodium chloride solution was added and the product extracted with ethyl acetate (3×100 ml). The organics were washed with water, dried over magnesium sulfate, filtered and concentrated in vacuo to afford (2,2-dimethyl-[1,3]dioxan-5-yl)-methanol (4.09 g, 76%) as a clear oil: 1H NMR (300 MHz, CDCl3) δ ppm 1.39 (s, 3H, CH3), 1.44 (s, 3H, CH3), 1.79-1.90 (m, 1H, CH), 2.15-2.26 (brs, 1H, OH), 3.69-3.81 (m, 2H, 2×OCH of 2×OCH2), 3.74 (d, J=6.8 Hz, 2H, OCH2), 3.96-4.05 (m, 2H, 2×OCH of 2×OCH2). was added the product extracted with ethyl acetate (3×100 ml) The organics were washed with water dried over magnesium sulfate filtered concentrated in vacuo

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To the solution of 2,2-dimethyl-[1,3]dioxane-5,5-dicarboxylic acid diethyl ester (19.75 g, 75.96 mmol) in dimethyl sulfoxide (80 ml) was added sodium chloride (4.4 g, 75.76 mmol) and water (2 ml). The reaction was refluxed for 7 h. After such time, it was poured into saturated sodium chloride solution (500 ml) and extracted with ether (4×200 ml). The combined organics were washed with water, dried over sodium sulfate, filtered and concentrated in vacuo. The residual oil was distilled under reduced pressure. Three fractions collected between 100° C. and 120° C. were combined to afford 2,2-dimethyl-[1,3]dioxane-5-carboxylic acid ethyl ester (7.58 g, 53%) as a clear oil (J. Org. Chem. 1986, 51, 2637) 1H NMR (300 MHz, CDCl3) δ ppm 1.26 (t, J=7.1 Hz, 3H, CH3), 1.41 (s, 3H, CH3), 1.44 (s, 3H, CH3), 2.74-2.85 (m, 1H, CH), 3.96-4.30 (m, 6H, 3×OCH2). The reaction was refluxed for 7 h extracted with ether (4×200 ml) The combined organics were washed with water dried over sodium sulfate filtered concentrated in vacuo The residual oil was distilled under reduced pressure Three fractions collected between 100° C. and 120° C.

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Lithium aluminum hydride (80 g) is stirred in ether (2000 ml) while the product of Example 3 (230 g) in ether (250 ml) is added dropwise. When the addition is complete the mixture is stirred an additional 16 hours. The reaction mixture is decomposed by careful addition of water (80 ml) followed by 15% aqueous sodium hydroxide (80 ml) and additional water (240 ml). The resulting suspension is filtered, the filter cake washed with ethanol and ether and the combined filtrates evaporated to give a residue. Distillation of the residue gives the title product (155 g) (81%) B.P. 75° C. (0.05 mm). is added dropwise When the addition The resulting suspension is filtered the filter cake washed with ethanol and ether the combined filtrates evaporated to give a residue Distillation of the residue