ethyl 3,3-dimethyloxirane-2-carboxylate

反応条件: temp:81.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Tosic acid monohydrate (0.132 g, 0.694 mmol) was dehydrated by aezotropic destillation with benzene (3×10 ml) in a rotary evaporator flushed with nitrogen. Thereafter benzene (100 ml) and ethyl 3,3-dimethyloxirane-2-carboxylate (1 g, 6.94 mmol) were added and the resulting mixture was stirred at reflux (81° C.) overnight. The clear reaction mixture was then cooled to room temperature, cooled to 4° C. for a couple of hours, and then filtered over a glass filter to remove the crystallized tosic acid. The filtrate was concentrated in vacuo (40° C., 50 mbar) to yield 778 mg of crude product (containing 2.5 wt % benzene) which was used without further purification in the next step. flushed with nitrogen The clear reaction mixture was then cooled to room temperature cooled to 4° C. for a couple of hours filtered over a glass filter to remove the crystallized tosic acid The filtrate was concentrated in vacuo (40° C., 50 mbar)

反応条件: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a stirred solution of propan-2-one (11.52 ml, 157 mmol) and ethyl 2-chloroacetate (25.04 ml, 235 mmol) in dry diethyl ether (125 ml) at −10° C. under nitrogen was added sodium ethoxide (10.66 g, 157 mmol) portionwise, keeping the temperature below 5° C. After addition was complete, the mixture was stirred for two hours at −10° C., whereafter the reaction was continued at room temperature for three hours. The reaction mixture was quenched with saturated aqueous ammonium chloride, the phases were separated, and the aqueous layer was extracted with diethyl ether (100 ml). The combined organic phases were dried over Na2SO4 and evaporated in vacuo). The resulting residue was purified by vacuum distillation. The major fraction (−25 mbar, 82° C.-85° C., 14.3 g) consisted of the desired product, containing 6.4 mol % ethyl chloroacetate. This was used in the next step without further purification. the temperature below 5° C After addition was continued at room temperature for three hours The reaction mixture was quenched with saturated aqueous ammonium chloride the phases were separated the aqueous layer was extracted with diethyl ether (100 ml) The combined organic phases were dried over Na2SO4 evaporated in vacuo) The resulting residue was purified by vacuum distillation The major fraction (−25 mbar, 82° C.-85° C., 14.3 g) containing 6.4 mol % ethyl chloroacetate This was used in the next step without further purification