| Summary: | 碩士 === 國立臺灣師範大學 === 化學研究所 === 88 === Ketones 1a-e、nitromethane 2 can react with the trapping reagents 4（thiophenol 4a, α-toluenthiol 4b or allyl mercaptan 4c）in the presence of catalytic amount of piperidine 3 to produce β-nitroalkylsulfides（5a-d, 6a-e or 7a-e）. By the use of CH2Cl2 as solvent and at 0 ℃, β-nitroalkylsulfides（5a-d, 6a-e or 7a-e）can be oxidized by m-chloroperoxybenzoic acid (m-CPBA) 8 to produce β-nitroalkyl sulfoxides（9a-d、10a-e or 11a-e）and subsequently elimination to produce 2,2-disubstituted 1-nitroalkenes 12a-e. The irreversibility of the synthetic mechanism not only could overcome the impracticability of the Henry reaction in the synthesis of 2,2-disubstituted 1-nitroalkenes 12a-b but also could produce the major product "exo-nitroolefins" 12c-e when cyclic ketones were used. By using this improved and easy methodology to prepare 2,2-disubstituted-1-nitroalkenes 12a-e, the yields of the products are medium to high. Under similar reaction conditions 5-substituted adamantan-2-ones 16a-f can also react with 2 in the presence of catalytic amount of piperidine 3 to produce 5-substituted-2-nitromethylene-admantanes 18a-f. 12b-e Also can be produced when β-nitroalkylsulfoxides（9b, 10c, 10d, 11c , and 11e）are treated with dilute aqueous basic solution, but the yields are lower than those of pyrolysis condition.
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