Tributylstannane → 4,4-Dimethoxy-1,5-dimethyl-8-oxa-bicyclo[3.2.1]oct-6-en-2-one

참여 물질

반응 단계

2.2 g (8.92 mmol) of 3-chloro-4,4-dimethoxy-1,5-dimethyl-8-oxa-bicyclo[3.2.1]oct-6-en-2-one in 240 ml of toluene are degassed, with heating at reflux temperature, and a catalytic amount of 66 mg of azaisobutyronitrile (AIBN) and a solution of 5.9 ml (22.3 mmol) of tributyltin hydride are added in succession. The reaction mixture is maintained at reflux temperature for a further 20 minutes to complete the reaction (TLC monitoring: hexane/ethyl acetate 4:1). The reaction mixture is then concentrated by evaporation under reduced pressure. The residue is then taken up in acetonitrile and the tin-containing residues are extracted by means of hexane. The acetonitrile phase is concentrated by evaporation in vacuo, 1.56 g (82.4% of theory) of 4,4-dimethoxy-1,5-dimethyl-8-oxa-bicyclo[3.2.1]oct-6-en-2-one remaining behind in the form of a yellow oil, which can be used for the next reaction step without further purification.

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