2-氧代四氢呋喃-3-羧酸甲酯

反应条件: temp:0.00; pressure:0.00; stir:

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

实验步骤: To a tetrahydrofuran solution (150 ml) of lithium hexamethyldisilazide prepared at −78° C. under an argon atmosphere from hexamethyl disilazane (55.4 ml, 262 mmol) and normal butyl lithium (2.62 M hexane solution, 100 ml, 262 mmol), a tetrahydrofuran solution (60 ml) of gamma butyrolactone (9.84 ml, 128 mmol) was added dropwise at −78° C. 10 minutes later, dimethyl carbonate (11.3 ml, 134 mmol) was added, followed by further stirring at room temperature for 10 hours. The reaction mixture was poured onto a mixture of concentrated hydrochloric acid (44 ml) and ice (500 g), followed by extraction twice with ethyl acetate. The extract was washed with brine, and subsequently dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure, to obtain the desired compound (pale brown oil, 15.1 g, 82%). followed by extraction twice with ethyl acetate The extract was washed with brine subsequently dried over sodium sulfate After filtering off the drying agent the filtrate was concentrated under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Cyclopropane-1,1-dicarboxylic acid (10 g) in acetonitrile(200 ml) was treated with triethylamine (43 ml) and iodomethane (19 ml) at room temperature. The solution was stirred for 2 h then heated at 75° C. for 16 h. The solvent was removed under reduced pressure, the residue dissolved in water, extracted with ethyl acetate, dried(MgSO4) and evaporated to a brown oil (6.70 g). The solvent was removed under reduced pressure the residue dissolved in water extracted with ethyl acetate, dried(MgSO4) evaporated to a brown oil (6.70 g)

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

实验步骤: To a tetrahydrofuran solution (150 ml) of lithium hexamethyldisilazide prepared at −78° C. under an argon atmosphere from hexamethyl disilazane (55.4 ml, 262 mmol) and normal butyl lithium (2.62 M hexane solution, 100 ml, 262 mmol), a tetrahydrofuran solution (60 ml) of gamma butyrolactone (9.84 ml, 128 mmol) was added dropwise at −78° C. 10 minutes later, dimethyl carbonate (11.3 ml, 134 mmol) was added, followed by further stirring at room temperature for 10 hours. The reaction mixture was poured onto a mixture of concentrated hydrochloric acid (44 ml) and ice (500 g), followed by extraction twice with ethyl acetate. The extract was washed with brine, and subsequently dried over sodium sulfate. After filtering off the drying agent, the filtrate was concentrated under reduced pressure, to obtain the desired compound (pale brown oil, 15.1 g, 82%). followed by extraction twice with ethyl acetate The extract was washed with brine subsequently dried over sodium sulfate After filtering off the drying agent the filtrate was concentrated under reduced pressure