Abstract |
(±)시스- 및 트란스-3-(2,2-디클로로비닐)-2,2-디메틸-1-시클로프로판 카르복시산 3-페녹시벤질을 2-메틸-3-부텐-2올(2)을 출발물질로하여 입체선택적으로 합성하였다. 아세트산과 무수아세트산의 존재하에서 2-메틸-3-부텐-2-올을 알릴자리옮김 반응에 의해 아세트산3-메틸-2-부텐-일(3)의 얻은 다음 이 아세트산 알릴(3)의 [3,3] 시그마 자리옮김 반응에 의해 γ,δ-불포화산(4)을 얻었다. 3,3-디메틸-4-펜텐산(4)을 SOCl2로 처리하고 3-페녹시벤질알코올로 에스테르화 시켜 알코올 부분이 구축된 3,3-디메틸-4-펜텐산 3-페녹시벤질(6)을 얻어서 사염화탄소의 첨가 후 그리화에 의해 (+)시스-및 트란스-3-(2,2-디클로로비닐)-2,2-디메틸-1-시클로프로 판카르복시산 3-페녹시벤질을 합성하였다. A stereoselective synthesis of 3-phenoxybenzyl (±)-cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid starting from readily available 2-methyl-3-buten-2-ol(2) is described. Allylic rearrangement of 2-methyl-3-buten-2-ol, in the presence of acetic acid and acetic anhydride gave 3-methyl-2-butenyl acetate(3). The [3,3] sigmatropic rearrangement of the allyl acetate(3), as the silylketene acetal, produced the γ,δ-unsaturated acid(4). Treatment of 3,3-dimethyl-4-pentenoic acid(4) with SOCl2 followed by esterification with 3-phenoxybenzyl alcohol yielded 3, 3-dimethyl-4-pentenoic acid ester(5). Addition of carbon tetrachloride to the olefin ester(6) furnished 4,6,6,6-tetrachloro-3,3-dimethylhexanoic acid ester (7). Cyclization with potassium t-butoxide and elimination of hydrogen chloride afforded 3-phenoxybenzyl (±) cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid. |
