6-溴色烷-4-醇

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 6-bromochroman-4-ol (3.98 kg, 17.4 mol) in toluene (18 L) add p-toluenesulfonic acid monohydrate (95 g, 499.42 mmol) at room temperature. Attach a Dean-Stark trap and reflux for 3 hr. and 50 min. Allow the mixture to cool to 50° C. in air and pour into saturated aqueous sodium bicarbonate (10 L) and ice (about 3 kg) with stirring. Separate the two layers. Back extract the aqueous layer with methyl tert-butyl ether (4 L). Wash the organic layer with saturated sodium bicarbonate (10 L) and brine (1×10 L), and evaporate the solvent under reduced pressure to obtain the title compound as a brown oil (4.90 kg, >100%, contains toluene). LCMS m/z (79Br) 209 [M+H]+. reflux for 3 hr 50 min Separate the two layers Back extract the aqueous layer with methyl tert-butyl ether (4 L) Wash the organic layer with saturated sodium bicarbonate (10 L) and brine (1×10 L) evaporate the solvent under reduced pressure

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

实验步骤: To a suspension of 7-bromo-3,4-dihydronaphthalen-1(2H)-one (3.95 kg, 17.4 mol) in ethanol (20 L) at room temperature add sodium borohydride (221 g, 5.84 mol) in portions over 3 hr. Concentrate the clear red solution. Add the residue into ice (about 3 kg) to form a suspension and then slowly add ice-cooled 0.5 M HCl (10 L) into the above suspension with stirring. Extract the mixture with methyl tert-butyl ether (20 L and 5 L). Wash the combined organic phase with saturated aqueous sodium bicarbonate (10 L) and brine (2×10 L), concentrate the solvent under reduced pressure and dry the wet solid in air overnight to obtain the title compound as a pale yellow solid (4.10 kg, quantitative). LC-ES/MS m/z 211 [M−H-2O+H]+. Concentrate the clear red solution Add the residue into ice (about 3 kg) to form a suspension Extract the mixture with methyl tert-butyl ether (20 L and 5 L) Wash the combined organic phase with saturated aqueous sodium bicarbonate (10 L) and brine (2×10 L) concentrate the solvent under reduced pressure dry the wet solid in air overnight