2,2-dimethyl-3,4-dihydrochromene

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

Procedure: A 4 mL vial was charged with 4-(2-bromophenyl)-2-methyl-2-butanol (97 mg, 0.40 mmol), Pd(dba)2 (11.5 mg, 0.02 mmol), Ph5FcP(t-Bu)2 (14.2 mg, 0.02 mmol) and sodium t-butoxide (46 mg, 0.48 mmol). Anhydrous toluene (2 mL) was added into the vial, and the vial was sealed with a cap containing a PTFE septum and removed from the drybox. The reaction mixture was stirred at room temperature for 10 min. The reaction solution was adsorbed onto silica gel and isolated by eluting with 5% ethyl acetate in hexanes to give 60 mg (93%) of 2,2-dimethylchroman as a colorless oil. was sealed with a cap removed from the drybox isolated by eluting with 5% ethyl acetate in hexanes

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

Procedure: To a solution of 1.6M n-butyllithium in hexane and 150 ml of diethyl ether were added a solution of 27 g of 2,2-dimethylchroman in diethyl ether over a one hour period at room temperature. The solution was then heated at reflux 160 minutes, cooled, and poured into dry ice/diethyl ether. The mixture was allowed to come to room temperature, poured into ice water, and layers separated. The organic layer was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 21 g of solid. The aqueous layer was acidified and the resulting precipitate extracted into diethyl ether/ethyl acetate. The organic extract was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 9 g of solid. The two isolated solids were combined and chromatographed over silica gel eluting with 10% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 9.8 g of the desired title intermediate, m.p. 90°-92° C. The solution was then heated at reflux 160 minutes cooled to come to room temperature separated The organic layer was washed with water dried over sodium sulfate concentrated in vacuo

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

Procedure: A solution of 5.0 g (30.82 mmol) of 2,2-dimethylchroman (Compound 56) in 50 ml of nitromethane was treated, under nitrogen, with 2.53 g (32.35 mmol) of acetyl chloride followed by 4.4 g (33 mmol) of aluminum chloride. The reaction mixture was stirred at room temperature for 3 hours and then cooled in an ice-bath and treated slowly with 50 ml of 6M HC1. The mixture was diluted with water and extracted with ether. The ether extracts were washed successively with saturated NaHCO3 solution, water and saturated NaCl solution and then dried (MgSO4). The solvent was removed in-vacuo and the resultant residue was purified by flash chromatography (silica; 10% ethyl acetate in hexane) to give the title compound as a white solid. PMR (CDCl3) : & 1.36 (6H, s), 1.84 (2H, t, J~6.8 Hz), 2.54 (3H, s), 2.82 (2H, t, J~6.8 Hz), 6.80 (1H, d, J~8.4 Hz), 7.69-7.76 (2H, m). MS exact mass, m/e 204.1140 (calcd. for C13H16O2, 204.1150). cooled in an ice-bath treated slowly with 50 ml of 6M HC1 extracted with ether The ether extracts were washed successively with saturated NaHCO3 solution, water and saturated NaCl solution dried (MgSO4) The solvent was removed in-vacuo the resultant residue was purified by flash chromatography (silica; 10% ethyl acetate in hexane)

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

Procedure: A mixture of 16 g (89 mmol) of 4-(2-hydroxyphenyl)-2-methyl-2-butanol, (Compound 55), 40 ml of conc. H2SO4 and 160 ml of water was heated at reflux for 4 hours. The mixture was cooled, diluted with 300 ml of water and extracted with 2×100 ml of hexane. The organic extracts were combined, washed successively with water and saturated NaCl solution and then dried. The solution was then filtered and the filtrate concentrated in-vacuo to give the title compound as a yellow oil. PMR (CDCl3) : & 1.32 (6H, s), 1.78 (2H, t, J~6.8 Hz), 2.76 (2H, t, J~6.8 Hz), 6.74-6.85 (2H, m), 7.01-7.12 (2H, m). was heated at reflux for 4 hours The mixture was cooled extracted with 2×100 ml of hexane washed successively with water and saturated NaCl solution dried The solution was then filtered the filtrate concentrated in-vacuo

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

Procedure: To a solution of 1.6M n-butyllithium in hexane and 150 ml of diethyl ether were added a solution of 27 g of 2,2-dimethylchroman in diethyl ether over a one hour period at room temperature. The solution was then heated at reflux 160 minutes, cooled, and poured into dry ice/diethyl ether. The mixture was allowed to come to room temperature, poured into ice water, and layers separated. The organic layer was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 21 g of solid. The aqueous layer was acidified and the resulting precipitate extracted into diethyl ether/ethyl acetate. The organic extract was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 9 g of solid. The two isolated solids were combined and chromatographed over silica gel eluting with 10% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 9.8 g of the desired title intermediate, m.p. 90°-92° C. The solution was then heated at reflux 160 minutes cooled to come to room temperature separated The organic layer was washed with water dried over sodium sulfate concentrated in vacuo

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

Procedure: To a solution of 1.6M n-butyllithium in hexane and 150 ml of diethyl ether were added a solution of 27 g of 2,2-dimethylchroman in diethyl ether over a one hour period at room temperature. The solution was then heated at reflux 160 minutes, cooled, and poured into dry ice/diethyl ether. The mixture was allowed to come to room temperature, poured into ice water, and layers separated. The organic layer was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 21 g of solid. The aqueous layer was acidified and the resulting precipitate extracted into diethyl ether/ethyl acetate. The organic extract was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 9 g of solid. The two isolated solids were combined and chromatographed over silica gel eluting with 10% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 9.8 g of the desired title intermediate, m.p. 90°-92° C. The solution was then heated at reflux 160 minutes cooled to come to room temperature separated The organic layer was washed with water dried over sodium sulfate concentrated in vacuo

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

Procedure: Using 2,2-dimethylchroman (19.7 g) and 5-chlorovaleryl chloride (20.7 g) according to the same method as that of Reference Example 1, the title compound was obtained as colorless crystals (22.0 g) having a melting point of 50 to 51° C.

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

Procedure: Using 2,2-dimethylchroman (19.7 g) and 5-chlorovaleryl chloride (20.7 g) according to the same method as that of Reference Example 1, the title compound was obtained as colorless crystals (22.0 g) having a melting point of 50 to 51° C.

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

Procedure: A 4 mL vial was charged with 4-(2-bromophenyl)-2-methyl-2-butanol (97 mg, 0.40 mmol), Pd(dba)2 (11.5 mg, 0.02 mmol), Ph5FcP(t-Bu)2 (14.2 mg, 0.02 mmol) and sodium t-butoxide (46 mg, 0.48 mmol). Anhydrous toluene (2 mL) was added into the vial, and the vial was sealed with a cap containing a PTFE septum and removed from the drybox. The reaction mixture was stirred at room temperature for 10 min. The reaction solution was adsorbed onto silica gel and isolated by eluting with 5% ethyl acetate in hexanes to give 60 mg (93%) of 2,2-dimethylchroman as a colorless oil. was sealed with a cap removed from the drybox isolated by eluting with 5% ethyl acetate in hexanes

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

Procedure: A 4 mL vial was charged with 4-(2-bromophenyl)-2-methyl-2-butanol (97 mg, 0.40 mmol), Pd(dba)2 (11.5 mg, 0.02 mmol), Ph5FcP(t-Bu)2 (14.2 mg, 0.02 mmol) and sodium t-butoxide (46 mg, 0.48 mmol). Anhydrous toluene (2 mL) was added into the vial, and the vial was sealed with a cap containing a PTFE septum and removed from the drybox. The reaction mixture was stirred at room temperature for 10 min. The reaction solution was adsorbed onto silica gel and isolated by eluting with 5% ethyl acetate in hexanes to give 60 mg (93%) of 2,2-dimethylchroman as a colorless oil. was sealed with a cap removed from the drybox isolated by eluting with 5% ethyl acetate in hexanes

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

Procedure: To a solution of 1.6M n-butyllithium in hexane and 150 ml of diethyl ether were added a solution of 27 g of 2,2-dimethylchroman in diethyl ether over a one hour period at room temperature. The solution was then heated at reflux 160 minutes, cooled, and poured into dry ice/diethyl ether. The mixture was allowed to come to room temperature, poured into ice water, and layers separated. The organic layer was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 21 g of solid. The aqueous layer was acidified and the resulting precipitate extracted into diethyl ether/ethyl acetate. The organic extract was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 9 g of solid. The two isolated solids were combined and chromatographed over silica gel eluting with 10% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 9.8 g of the desired title intermediate, m.p. 90°-92° C. The solution was then heated at reflux 160 minutes cooled to come to room temperature separated The organic layer was washed with water dried over sodium sulfate concentrated in vacuo

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

Procedure: To a solution of 1.6M n-butyllithium in hexane and 150 ml of diethyl ether were added a solution of 27 g of 2,2-dimethylchroman in diethyl ether over a one hour period at room temperature. The solution was then heated at reflux 160 minutes, cooled, and poured into dry ice/diethyl ether. The mixture was allowed to come to room temperature, poured into ice water, and layers separated. The organic layer was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 21 g of solid. The aqueous layer was acidified and the resulting precipitate extracted into diethyl ether/ethyl acetate. The organic extract was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 9 g of solid. The two isolated solids were combined and chromatographed over silica gel eluting with 10% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 9.8 g of the desired title intermediate, m.p. 90°-92° C. The solution was then heated at reflux 160 minutes cooled to come to room temperature separated The organic layer was washed with water dried over sodium sulfate concentrated in vacuo