Use of 1,3-Dioxin-4-ones and Related Compounds in Synthesis. XXXVIII. Use of 1,3-Dioxin-4-ones Having a Fluorine or Trifluoromethyl Group at the 5-Position as .PI.2 Components in (2+2)-Photocycloaddition and Diels-Alder Reactions.
Fluorination of 5,6-unsubstituted 1,3-dioxin-4-ones by fluorine followed by treatment with triethylamine affords the title compounds, which can be converted into fluorinated derivatives of either formylacetic acid or of heterocyclic systems.
Iwaoka Tomoyasu, Katagiri Nobuya, Sato Masayuki, Kaneko Chikara, Chem. and Pharm. Bull., 40 (1992) N 9, S 2319-2324
作者:Iwaoka Tomoyasu, Katagiri Nobuya, Sato Masayuki, Kaneko Chikara
DOI:——
日期:——
Iwaoka Tomoyasu, Murohashi Tomoko, Sato Masayuki, Kaneko Chikara, Synthesis, (1992) N 10, S 977-981
作者:Iwaoka Tomoyasu, Murohashi Tomoko, Sato Masayuki, Kaneko Chikara
DOI:——
日期:——
Use of 1,3-Dioxin-4-ones and Related Compounds in Synthesis. XXXVIII. Use of 1,3-Dioxin-4-ones Having a Fluorine or Trifluoromethyl Group at the 5-Position as .PI.2 Components in (2+2)-Photocycloaddition and Diels-Alder Reactions.
1, 3-Dioxin-4-ones having fluorine or a trifluoromethyl group at the 5-position were used as the π2 components in Diels-Alder reactions with 1-oxygenated dienes. Use of high-perssure conditions was the essential requisite. While the 5-flurodioxinones were photolabile, the corresponding trifluoromethyl derivatives participated as the enone components in [2+2]photocycloaddition to alkenes, Ring-opening reactions of these adducts by acetal bond cleavage gave cyclobutanes and cyclohexanes. Diels-Alder reactions of the fluorinated homochiral dioxinones having l-menthone at the acetal position with Danishefsky diene proceeded in a completely diastereoselective manner to give single adducts.
Fluorination of 5,6-unsubstituted 1,3-dioxin-4-ones and their 6-substituted derivatives by molecular fluorine followed by treatment with an appropriate organic base affords the title compounds, which can be converted either into heterocyclic compounds or into acylacetic acid derivatives having a fluorine atom.