ethyl 2-(3,4-dihydro-1H-isochromen-1-yl)acetate

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

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

Procedure: Ethyl 2-(2-hydroxyethyl)cinnamate (CXXX, EXAMPLE 112, theoretically 2.40 moles) is dissolved in THF (2.4 liters) and cooled to 0°. Potassium t-butoxide (5 mol %, 120 ml of a 1 molar THF solution) is added via syringe. After 5 min HPLC shows the cyclization is completed. Acetic acid (6 mol %, 8.2 ml, 144 mmol) is added. The slurry is filtered through approximately 300 g of 200 mesh silica gel. The solvent is Diatomaceous earth (100 g) is added followed by hexane (4.5 liters). This slurry is filtered through 200 mesh silica gel (400 g), washing with THF/hexane (1/9) until TLC shows no remaining product. Solvent removal gives the title compound. This material is filtered through silica gel more carefully, giving an analytical sample of the title compound, NMR (300 MHz, CDCl3) 7.1-7.2, 7.05, 5.26, 4.23, 4.12, 3.83, 3.0-2.7, 1.28; high resolution MS calculated for 220.1099, found 220.1105. cooled to 0° The slurry is filtered through approximately 300 g of 200 mesh silica gel is added This slurry is filtered through 200 mesh silica gel (400 g) washing with THF/hexane (1/9) until TLC Solvent removal

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: Ethyl 2-(2-hydroxyethyl)cinnamate (CXXX, EXAMPLE 112, theoretically 2.40 moles) is dissolved in THF (2.4 liters) and cooled to 0°. Potassium t-butoxide (5 mol %, 120 ml of a 1 molar THF solution) is added via syringe. After 5 min HPLC shows the cyclization is completed. Acetic acid (6 mol %, 8.2 ml, 144 mmol) is added. The slurry is filtered through approximately 300 g of 200 mesh silica gel. The solvent is Diatomaceous earth (100 g) is added followed by hexane (4.5 liters). This slurry is filtered through 200 mesh silica gel (400 g), washing with THF/hexane (1/9) until TLC shows no remaining product. Solvent removal gives the title compound. This material is filtered through silica gel more carefully, giving an analytical sample of the title compound, NMR (300 MHz, CDCl3) 7.1-7.2, 7.05, 5.26, 4.23, 4.12, 3.83, 3.0-2.7, 1.28; high resolution MS calculated for 220.1099, found 220.1105. cooled to 0° The slurry is filtered through approximately 300 g of 200 mesh silica gel is added This slurry is filtered through 200 mesh silica gel (400 g) washing with THF/hexane (1/9) until TLC Solvent removal

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:

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

Procedure: To a solution of (±)-isochroman-1-yl-acetic acid ethyl ester (1.90 g, 8.63 mmol, 1 eq.) in THF (40 mL) and MeOH (10 mL), 1M aq. NaOH soln. (17.3 mL, 17.3 mmol, 2 eq.) was added. The pale yellow solution was stirred at r.t. for 2 hours, then the organic solvents were removed in vacuo. The aq. layer was washed with AcOEt (1×10 mL). The aq. layer was acidified with 1N aq. HCl (pH=1). The resulting emulsion was extracted with DCM (3×25 mL). The comb. org. phases were dried over MgSO4 and concentrated in vacuo to give the title compound as a colorless oil that solidifies upon standing. The product was used without further purification. (17.3 mL, 17.3 mmol, 2 eq.) was added the organic solvents were removed in vacuo The aq. layer was washed with AcOEt (1×10 mL) The resulting emulsion was extracted with DCM (3×25 mL) phases were dried over MgSO4 concentrated in vacuo

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

Procedure: To an ice-cooled solution of phenethyl alcohol (1.21 mL, 10 mmol, 1.0 eq.) and ethyl 3,3-diethoxy-propionate (2.59 mL, 12 mmol, 1.2 eq) in DCM (5 mL), 1N titantetrachloride solution in DCM (22 mL, 22 mmol, 2.2 eq) was added dropwise. The mixture was stirred at 0° C. for 1 hour and further at r.t. for 3 hours. The mixture was poured onto ice and 2N aq. HCl soln. (30 mL). The layers were separated. The aq. phase was extracted with DCM (2×50 mL). The comb. org. phases were washed with sat. aq. NaCl soln. (1×50 mL), dried over Na2SO4, and concentrated in vacuo. The residue was purified by flashmaster (column: 100 g, flow: 45 mL/min, 40 fractions of 45 mL, Heptane to Heptane/AcOEt 85:15) to yield (±)-isochroman-1-yl-acetic acid ethyl ester as a colorless oil. was added dropwise The layers were separated The aq. phase was extracted with DCM (2×50 mL) phases were washed with sat. aq. NaCl soln (1×50 mL), dried over Na2SO4 concentrated in vacuo The residue was purified by flashmaster (column: 100 g, flow: 45 mL/min, 40 fractions of 45 mL, Heptane to Heptane/AcOEt 85:15)

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

Procedure: Ethyl 2-(2-hydroxyethyl)cinnamate (CXXX, EXAMPLE 112, theoretically 2.40 moles) is dissolved in THF (2.4 liters) and cooled to 0°. Potassium t-butoxide (5 mol %, 120 ml of a 1 molar THF solution) is added via syringe. After 5 min HPLC shows the cyclization is completed. Acetic acid (6 mol %, 8.2 ml, 144 mmol) is added. The slurry is filtered through approximately 300 g of 200 mesh silica gel. The solvent is removed under reduced pressure until approximately 0.5 liter of THF remained. Diatomaceous earth (100 g) is added followed by hexane (4.5 liters). This slurry is filtered through 200 mesh silica gel (400 g), washing with THF/hexane (1/9) until TLC shows no remaining product. Solvent removal gives the title compound. This material is filtered through silica gel more carefully, giving an analytical sample of the title compound, NMR (300 MHz, CDCl3) 7.1-7.2, 7.05, 5.26, 4.23, 4.12, 3.83, 3.0-2.7, 1.28; high resolution MS calculated for 220.1099, found 220.1105. cooled to 0° The slurry is filtered through approximately 300 g of 200 mesh silica gel The solvent is removed under reduced pressure until approximately 0.5 liter of THF Diatomaceous earth (100 g) is added This slurry is filtered through 200 mesh silica gel (400 g) washing with THF/hexane (1/9) until TLC Solvent removal

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: Ethyl 2-(2-hydroxyethyl)cinnamate (CXXX, EXAMPLE 112, theoretically 2.40 moles) is dissolved in THF (2.4 liters) and cooled to 0°. Potassium t-butoxide (5 mol %, 120 ml of a 1 molar THF solution) is added via syringe. After 5 min HPLC shows the cyclization is completed. Acetic acid (6 mol %, 8.2 ml, 144 mmol) is added. The slurry is filtered through approximately 300 g of 200 mesh silica gel. The solvent is Diatomaceous earth (100 g) is added followed by hexane (4.5 liters). This slurry is filtered through 200 mesh silica gel (400 g), washing with THF/hexane (1/9) until TLC shows no remaining product. Solvent removal gives the title compound. This material is filtered through silica gel more carefully, giving an analytical sample of the title compound, NMR (300 MHz, CDCl3) 7.1-7.2, 7.05, 5.26, 4.23, 4.12, 3.83, 3.0-2.7, 1.28; high resolution MS calculated for 220.1099, found 220.1105. cooled to 0° The slurry is filtered through approximately 300 g of 200 mesh silica gel is added This slurry is filtered through 200 mesh silica gel (400 g) washing with THF/hexane (1/9) until TLC Solvent removal

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