Total Syntheses of Marine Furanosesquiterpenoids, Tubipofurans
摘要:
The first total syntheses of marine furanosesquiterpenoids, tubipofuran (1) and 15-acetoxytubipofuran (2), have been achieved via the common intermediate 3. The syntheses were begun by our newly improved fused 3-methylfuran construction method by the reaction of allenic sulfonium salt with the enolate anion of a cyclic 1,3-diketone. Using this fused furan synthesis, multigram quantities of bicyclic 3-methylfurans were readily obtained in only one step. The cis-fused furanodecalin system was constructed by the regioselective Diels-Alder reaction of benzofuran-quinone 5 and Danishefsky diene 4. The Diels-Alder adduct 9 was transformed into the intermediate 3 by sequential radical deoxygenations of the two hydroxy groups derived from benzofuranquinone 5.
Furannulation strategy for synthesis of the naturally occurring fused 3-methylfurans: efficient synthesis of evodone and menthofuran and regioselective synthesis of maturone via a Lewis acid catalyzed Diels-Alder reactions. Some comments for its mechanistic aspects
摘要:
Fused 3-methylfurans are readily obtained by the reaction of allenic sulfonium salt 1 and the enolate anions of cyclic 1,3-dicarbonyl compounds in two steps. Using these fused 3-methylfuran compounds as intermediates, furanoterpenoids such as menthofuran (8) and evodone (4b) are synthesized efficiently. Moreover, maturone (15) is also obtained regioselectivity by Lewis acid CatalYzed Diels-Alder reaction of benzofuranquinone (12) with piperylene. In the context with the regioselectivity observed in the Diels-Alder reaction of 12, semiempirical molecular orbital calculations are applied to gain its theoretical interpretation based upon frontier molecular orbital theory and transition state analysis.
Furannulation strategy for synthesis of the naturally occurring fused 3-methylfurans: efficient synthesis of evodone and menthofuran and regioselective synthesis of maturone via a Lewis acid catalyzed Diels-Alder reactions. Some comments for its mechanistic aspects
作者:Mariko Aso、Akio Ojida、Guang Yang、Ok Ja Cha、Eiji Osawa、Ken Kanematsu
DOI:10.1021/jo00067a031
日期:1993.7
Fused 3-methylfurans are readily obtained by the reaction of allenic sulfonium salt 1 and the enolate anions of cyclic 1,3-dicarbonyl compounds in two steps. Using these fused 3-methylfuran compounds as intermediates, furanoterpenoids such as menthofuran (8) and evodone (4b) are synthesized efficiently. Moreover, maturone (15) is also obtained regioselectivity by Lewis acid CatalYzed Diels-Alder reaction of benzofuranquinone (12) with piperylene. In the context with the regioselectivity observed in the Diels-Alder reaction of 12, semiempirical molecular orbital calculations are applied to gain its theoretical interpretation based upon frontier molecular orbital theory and transition state analysis.
作者:Aso, Mariko、Sakamoto, Mizue、Urakawa, Narumi、Kanematsu, Ken
DOI:——
日期:——
ASO, MARIKO;SAKAMOTO, MIZUE;URAKAWA, NARUMI;KANEMATSU, KEN, HETEROCYCLES, 31,(1990) N, C. 1003-1006
作者:ASO, MARIKO、SAKAMOTO, MIZUE、URAKAWA, NARUMI、KANEMATSU, KEN
DOI:——
日期:——
Total Syntheses of Marine Furanosesquiterpenoids, Tubipofurans
作者:Akio Ojida、Fumiyo Tanoue、Ken Kanematsu
DOI:10.1021/jo00099a028
日期:1994.10
The first total syntheses of marine furanosesquiterpenoids, tubipofuran (1) and 15-acetoxytubipofuran (2), have been achieved via the common intermediate 3. The syntheses were begun by our newly improved fused 3-methylfuran construction method by the reaction of allenic sulfonium salt with the enolate anion of a cyclic 1,3-diketone. Using this fused furan synthesis, multigram quantities of bicyclic 3-methylfurans were readily obtained in only one step. The cis-fused furanodecalin system was constructed by the regioselective Diels-Alder reaction of benzofuran-quinone 5 and Danishefsky diene 4. The Diels-Alder adduct 9 was transformed into the intermediate 3 by sequential radical deoxygenations of the two hydroxy groups derived from benzofuranquinone 5.