2-甲基-4-(苯硫基)-2-丁醇

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of 15.00 grams (0.076 mol) of 2-methyl-4-(phenylthio)-2-butanol, 12.75 grams of H3PO4, 27.0 grams (0.190 mol) of P2O5 [this is added in three equal portions every 8 h]and 60 mL of sodium-dried benzene was boiled under N2 for 24 hours in a 250-mL, round-bottom flask equipped with a condenser and nitrogen inlet. The resulting, cooled heterogeneous mixture was separated and the P2O5 layer was extracted with ether. The combined organic layers were washed with H2O, brine, dried with Na2SO4 (4 h). Evaporation and vacuum distillation gave 11.68 grams (86.0%) of 4,4-dimethylthiochroman as a clear colorless liquid: bp 75°-82° C./0.1 mm; 1H NMR (DCCl3) δ1.29 [s, 6 H, (CH3)2C]1.92 [m, 2 H, ArSCH2CH2 ]3.00 [m, 2 H, ArSCH2CH2 ]6.90-7.32 [m, 4 H, Ar-H]; 13C NMR (DCCl3) ppm 22.8 [ArSCH2CH2 ], 29.9 [(CH3)2C]32.6 [(CH3)C], 37.4 [ArSCH2CH2 ], 123.7, 125.7, 126.1, 126.2, 131.5, 141.5. ##STR13## equipped with a condenser and nitrogen inlet The resulting, cooled heterogeneous mixture was separated the P2O5 layer was extracted with ether The combined organic layers were washed with H2O, brine dried with Na2SO4 (4 h) Evaporation and vacuum distillation

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 4-bromo-2-methyl-2-trimethylsilyloxybutane (9) (12 g) in methanol (55 ml) at room temperature was added ethanolic hydrogen chloride (ca. 1M, 0.2 ml). After 10 minutes the solution was concentrated in vacuo (at room temperature) to constant weight. The residue was taken up in chloroform and reconcentrated to constant weight to give 4-bromo-2-methyl-2-butanol (H, y=1, R1 =R2 =Me) as a chromatographically homogenous oil. The product was dissolved in THF (10 ml) and added to a premixed, stirred solution of potassium tert-butoxide (3.7 g) and thiophenol (3.6 ml) in N,N-dimethylformamide (50 ml) at room temperature. After a few minutes a precipitate started forming, and after 30 minutes the mixture was partitioned between ethyl acetate (300 ml) and water (200 ml). The organic layer was washed consecutively with 2N sodium hydroxide solution, water and brine. Drying and concentration in vacuo gave 3-hydroxy-3-methylbutyl phenyl sulphide as a chromatographically homogenous oil. This was dissolved in methanol (60 ml), and to the stirred solution was added sodium hydrogen carbonate (4.7 g), aqueous sodium tungstate solution (2%, 5 ml) and hydrogen peroxide (100 vol, 11.8 ml). The initial exothermic reaction which ensued was checked by momentary ice-cooling. The reaction mixture was then-stirred at 50° C. for 1 hour. After cooling the mixture was partitioned between dichloromethane (200 ml) and water. The aqueous layer was extracted with more dichloromethane, and the combined dichloromethane layers were washed with water, brine, and dried. Concentration in vacuo gave a crude product which was purified by chromatography (150 g silica gel; ether as eluant) to give the sulphone (21) as a viscous oil, 6 (300 MHz) 1.22 (6H, s), 1.64 (1H, bs), 1.88 (2H, m), 3.25 (2H, m), 7.55-7.70 (3H, m), 7.93 (2H, m). added to a premixed After a few minutes a precipitate started forming after 30 minutes the mixture was partitioned between ethyl acetate (300 ml) and water (200 ml) The organic layer was washed consecutively with 2N sodium hydroxide solution, water and brine Drying concentration in vacuo

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of 15.00 grams (0.076 mol) of 2-methyl-4-(phenylthio)-2-butanol, 12.75 grams of H3PO4, 27.0 grams (0.190 mol) of P2O5 [this is added in three equal portions every 8 h] and 60 mL of sodium-dried benzene was boiled under N2 for 24 hours in a 250-mL, round-bottom flask equipped with a condenser and nitrogen inlet. The resulting, cooled heterogeneous mixture was separated and the P2O5 layer was extracted with ether. The combined organic layers were washed with H2O, brine, dried with Na2SO4 (4 h). Evaporation and vacuum distillation gave 11.68 grams (86.0%) of 4,4-dimethylthiochroman as a clear colorless liquid: bp 75°-82° C./0.1 mm; 1H NMR (DCCl3) δ1.29 [s, 6H, (CH3)2C] 1.92 [m, 2H, ArSCH2CH2 ] 3.00 [m, 2H, ArSCH2CH2 ] 6.90-7.32 [m, 4H, Ar--H]; 13C NMR (DCCl3) ppm 22.8 [ArSCH2CH2 ], 29.9 [(CH3)2C] 32.6 [(CH3)C], 37.4 [ArSCH2CH2 ], 123.7, 125.7, 126.1, 126.2, 131.5, 141.5. ##STR13## equipped with a condenser and nitrogen inlet The resulting, cooled heterogeneous mixture was separated the P2O5 layer was extracted with ether The combined organic layers were washed with H2O, brine dried with Na2SO4 (4 h) Evaporation and vacuum distillation