ethyl 3,3-diethoxypropanoate

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

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

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Small pellets of solid NaOH (5.00 g, 125 mmol) were slowly added to a mixture of ethyl 3,3-diethoxypropionate (19.02 g, 100 mmol) and water (35 mL). As the NaOH dissolved the mixture became a homogeneous solution. The solution was heated to 110° C. for 30 min. The reaction was allowed to cool to ambient temperature and then chilled with an ice-water bath. The solution was acidified with drop-wise addition of concentrated aqueous HCl (9.37 mL, 113 mmol). The solution was allowed to warm to ambient temperature and then extracted with dichloromethane (4×15 mL). The combined organic extracts were washed with brine (15 mL), dried over MgSO4, filtered, and concentrated under reduced pressure to yield 15.11 g of 3,3-diethoxypropionic acid as a yellow oil. to cool to ambient temperature chilled with an ice-water bath to warm to ambient temperature extracted with dichloromethane (4×15 mL) The combined organic extracts were washed with brine (15 mL) dried over MgSO4 filtered concentrated under reduced pressure

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

Procedure: Titanium tetrachloride (1M in methylene chloride, 90 ml, 90.0 mmol) is added over a period of 20 minutes to an ice-cooled mixture of phenethyl alcohol (XLV, 4.9 ml, 41.0 mmol), ethyl 3,3-diethoxypropionate (LXXV, 9.1 ml, 46.8 mmol) and nitromethane (17 ml). The mixture is stirred for 2 hr and then concentrated, diluted with ether, poured into ice/hydrochloric acid (1N), and allowed to stir. The phases are separated and the aqueous phase is extracted three times with ether. The combined organic phases are backwashed with saline, dried over magnesium sulfate and concentrated. The residue is chromatographed on silica gel eluting with ethyl acetate/hexane (10/90). The appropriate fractions are pooled and concentrated to give ethyl (±)-(isochroman-1-yl)acetate (LXXVII), NMR (CDCl3) 1.28, 2.68-3.04, 3.82, 4.13, 4.22, 5.26, 7.05 and 7.16 δ. cooled concentrated diluted with ether poured into ice/hydrochloric acid (1N) to stir The phases are separated the aqueous phase is extracted three times with ether dried over magnesium sulfate concentrated The residue is chromatographed on silica gel eluting with ethyl acetate/hexane (10/90) concentrated

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

Procedure: Titanium tetrachloride (1M in methylene chloride, 51 ml) is added over a period of 10 min to an ice-cooled mixture of 2-(3-bromophenyl)ethanol (XLV, 4.34 g, 21.6 mmol) and ethyl 3,3-diethoxypropionate (LXXXV, 4.93 g, 25.9 mmol) in nitromethane (5 ml). After stirring for 10 min, the ice bath is removed and the mixture is allowed to stir at 20-25° for 5 hr, at which time it is poured onto ice/aqueous hydrochloric acid (~1N). The mixture is extracted with dichloromethane and backwashed with hydrochloric acid (0.5N)/saline and saline. The organic phase is separated dried over sodium sulfate, concentrated, and the residue chromatographed on silica gel eluting with ethyl acetate/hexane (5/95). The appropriate fractions are pooled and concentrated to give ethyl (6-bromoisochroman-1-yl)acetate (LXXVII), NMR (CDCl3) 1.28, 2.66-2.87, 2.96, 3.768, 3.807, 4.11, 4.21, 5.19, 6.93 and 7.28 δ. cooled the ice bath is removed to stir at 20-25° for 5 hr, at which time it is poured onto ice/aqueous hydrochloric acid (~1N) The mixture is extracted with dichloromethane The organic phase is separated dried over sodium sulfate concentrated the residue chromatographed on silica gel eluting with ethyl acetate/hexane (5/95) concentrated

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirring solution of 1-(2-methoxyethyl)thiourea (21.38 g, 159.3 mmol) and ethyl 3,3-diethoxypropanoate (46.5 mL, 239.0 mmol) in MeOH (300 mL) was added a freshly prepared solution of 0.96N sodium methoxide in MeOH (250 mL, 239.0 mmol) dropwise over 30 minutes at room temperature under argon. The reaction mixture was heated to 60° C. for 45 minutes and cooled to room temperature. Solvent was removed under reduced pressure and toluene (250 mL) was added to the residue. The mixture was stirred at reflux for an additional 3 hours and then cooled to room temperature. Water (200 mL) was added and the layers were separated. The aqueous layer was washed with CH2Cl2 (50 mL), neutralized with 2N aqueous HCl and extracted with CH2Cl2 (3×200 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The residue was recrystallized from i-PrOH (200 mL) to give the title compound (13.3 g, 45%) as a light yellow crystalline solid. cooled to room temperature Solvent was removed under reduced pressure and toluene (250 mL) was added to the residue at reflux for an additional 3 hours cooled to room temperature Water (200 mL) was added the layers were separated The aqueous layer was washed with CH2Cl2 (50 mL) extracted with CH2Cl2 (3×200 mL) The combined organic layers were dried over Na2SO4 concentrated in vacuo The residue was recrystallized from i-PrOH (200 mL)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 250 mL round-bottomed flask with magnetic stirring that contained ethyl 3,3-diethoxypropanoate (20.0 g, 102.0 mmol, colourless oil, 97%), a previously prepared solution of NaOH (5.23 g, 131.0 mmol) in H2O (30 mL) was added. The resulting mixture was stirred to reflux (100° C.) during 1 h. After allowing it to temper, the mixture was acidified using HCl 37% and it was extracted with AcOEt, 8×20 mL. The resulting organic phase was washed with 1×20 mL NaCl sat., dried with Na2SO4, filtered and concentrated to dryness. The obtained oil was confirmed to correspond to the title compound (15.9 g, 98.0 mmol, 96%). The resulting mixture was stirred was extracted with AcOEt, 8×20 mL The resulting organic phase was washed with 1×20 mL NaCl sat. dried with Na2SO4 filtered concentrated to dryness

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

Procedure: To a solution of 25 g of ethyl 3,3-diethoxypropionate (131 mmol) in 79 mL of methanol there are added 13.1 mL of aqueous 35% sodium hydroxide solution (452 mmol). The reaction mixture is stirred at ambient temperature for 3 hours. The reaction mixture is then concentrated to remove the methanol. After dissolving the undissolved material by adding water, aqueous 5N HCl solution is added to obtain a pH of 5. Dichloromethane is added and then the organic phase is washed with brine. After drying over MgSO4 and concentrating to dryness, the title product is obtained in the form of an oil which is used in the next Step without being otherwise purified. The reaction mixture is then concentrated to remove the methanol After dissolving the undissolved material by adding water, aqueous 5N HCl solution is added to obtain a pH of 5 the organic phase is washed with brine After drying over MgSO4 concentrating to dryness

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl 3,3-diethoxypropanoate (4.2 g, 22.0 mmol, 1 eq) and NaOH (1.1 g, 28 mmol, 1.3 eq) in water (8 mL) was heated in a 110° C. oil bath for 1.25 h. The reaction was then cooled to 0° C. and was stirred with concentrated HCl (2.3 mL) and EtOAc (20 mL). The organic layer was saved, and the aqueous layer was extracted with CH2Cl2. The combined organic layers were dried over MgSO4, filtered, and evaporated to afford 3,3-diethoxypropanoic acid (3.41 g, 96% yield) as an orange oil, which was used in the next step without any further purification. the aqueous layer was extracted with CH2Cl2 The combined organic layers were dried over MgSO4 filtered evaporated

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of ethyl 3,3-diethoxypropanoate (4.2 g, 22.0 mmol, 1 eq) and NaOH (1.1 g, 28 mmol, 1.3 eq) in water (8 mL) was heated in a 110° C. oil bath for 1.25 h. The reaction was then cooled to 0° C. and was stirred with concentrated HCl (2.3 mL) and EtOAc (20 mL). The organic layer was saved, and the aqueous layer was extracted with CH2Cl2. The combined organic layers were dried over MgSO4, filtered, and evaporated to afford 3,3-diethoxypropanoic acid (3.41 g, 96% yield) as an orange oil, which was used in the next step without any further purification. the aqueous layer was extracted with CH2Cl2 The combined organic layers were dried over MgSO4 filtered evaporated

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Small pellets of solid NaOH (5.00 g, 125 mmol) were slowly added to a mixture of ethyl 3,3-diethoxypropionate (19.02 g, 100 mmol) and water (35 mL). As the NaOH dissolved the mixture became a homogeneous solution. The solution was heated to 110° C. for 30 min. The reaction was allowed to cool to ambient temperature and then chilled with an ice-water bath. The solution was acidified with drop-wise addition of concentrated aqueous HCl (9.37 mL, 113 mmol). The solution was allowed to warm to ambient temperature and then extracted with dichloromethane (4×15 mL). The combined organic extracts were washed with brine (15 mL), dried over MgSO4, filtered, and concentrated under reduced pressure to yield 15.11 g of 3,3-diethoxypropionic acid as a yellow oil. to cool to ambient temperature chilled with an ice-water bath to warm to ambient temperature extracted with dichloromethane (4×15 mL) The combined organic extracts were washed with brine (15 mL) dried over MgSO4 filtered concentrated under reduced pressure

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

Procedure: Titanium tetrachloride (1M in methylene chloride, 90 ml, 90.0 mmol) is added over a period of 20 minutes to an ice-cooled mixture of phenethyl alcohol (XLV, 4.9 ml, 41.0 mmol), ethyl 3,3-diethoxypropionate (LXXV, 9.1 ml, 46.8 mmol) and nitromethane (17 ml). The mixture is stirred for 2 hr and then concentrated, diluted with ether, poured into ice/hydrochloric acid (1N), and allowed to stir. The phases are separated and the aqueous phase is extracted three times with ether. The combined organic phases are backwashed with saline, dried over magnesium sulfate and concentrated. The residue is chromatographed on silica gel eluting with ethyl acetate/hexane (10/90). The appropriate fractions are pooled and concentrated to give ethyl (±)-(isochroman-1-yl)acetate (LXXVII), NMR (CDCl3) 1.28, 2.68-3.04, 3.82, 4.13, 4.22, 5.26, 7.05 and 7.16 δ. cooled concentrated diluted with ether poured into ice/hydrochloric acid (1N) to stir The phases are separated the aqueous phase is extracted three times with ether dried over magnesium sulfate concentrated The residue is chromatographed on silica gel eluting with ethyl acetate/hexane (10/90) concentrated