The first total synthesis of （+）-5α-hydroxy-isopterocarpolone （1）, an oxygenated eudesmane isolated from Chinese folk medicine Artemisia eriopoda, starting from （+）-dihydrocarvone（2） was described. Compound 4...The first total synthesis of （+）-5α-hydroxy-isopterocarpolone （1）, an oxygenated eudesmane isolated from Chinese folk medicine Artemisia eriopoda, starting from （+）-dihydrocarvone（2） was described. Compound 4 was stereoselectively prepared from compound 2 in three steps according to reference-. The treatment of tosylhydrazone 5, which was formed via the reaction of compound 4 and TsNHNH2 catalyzed by BF3-5Et2O, with an excess of n-butyllithium gave triene 6. Oxidation of triene 6 with singlet oxygen afforded the desired endo-peroxide 7 as a single product. Reductive cleavage of peroxide 7 with K2CO3 gave α-rotunol 3, a natural eudesmane firstly isolated in 1969. Hydrolysis of α-rotunol 3 with 10% sulfuric acid afforded （+）-5α-hydroxy-isopterocarpolone （1）. The structures of all the compounds were confirmed by IR, MS and NMR spectra.展开更多
A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)...A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.展开更多
14-Noreudesma-4,11-dien-3,9-diones′ analogues were treated with DDQ in dioxane and afforded the rearranged aromatic products. The similar compounds to eudesma-4,11-dien-3,9-diones had no reaction. 9-Actoxy-14-noreude...14-Noreudesma-4,11-dien-3,9-diones′ analogues were treated with DDQ in dioxane and afforded the rearranged aromatic products. The similar compounds to eudesma-4,11-dien-3,9-diones had no reaction. 9-Actoxy-14-noreudesma-4,11-dien-3-ones, 9-actoxy-eudesma-4,11-dien-3-ones and their analogues yielded the normal 1,2-dehydro-products. The mechanism of the rearrangement was discussed.展开更多
The selective epoxidation of 3,3-(1,2-ethanediyl-bisoxy)-5(10),9(11)-estradiene-17-α-(1-propynyl)-17-β-ol with Fe(Ⅱ)Pc/PhIO was investigated at 25 ℃? atmospheric pressure. With a molar ratio of Fe(Ⅱ)Pc∶compound...The selective epoxidation of 3,3-(1,2-ethanediyl-bisoxy)-5(10),9(11)-estradiene-17-α-(1-propynyl)-17-β-ol with Fe(Ⅱ)Pc/PhIO was investigated at 25 ℃? atmospheric pressure. With a molar ratio of Fe(Ⅱ)Pc∶compound(I)∶PhIO at 6.25∶50∶120, the conversion reaches 100%. The overall yield of the products 5α, 10α-epoxide(2) and 5β, 10β-epoxide(3)is 60%, and the molar ratio of 2 to 3 is {8.39∶}1. The product 5α, 10α-epoxide is identified by melting point and HPLC.展开更多
文摘The first total synthesis of （+）-5α-hydroxy-isopterocarpolone （1）, an oxygenated eudesmane isolated from Chinese folk medicine Artemisia eriopoda, starting from （+）-dihydrocarvone（2） was described. Compound 4 was stereoselectively prepared from compound 2 in three steps according to reference-. The treatment of tosylhydrazone 5, which was formed via the reaction of compound 4 and TsNHNH2 catalyzed by BF3-5Et2O, with an excess of n-butyllithium gave triene 6. Oxidation of triene 6 with singlet oxygen afforded the desired endo-peroxide 7 as a single product. Reductive cleavage of peroxide 7 with K2CO3 gave α-rotunol 3, a natural eudesmane firstly isolated in 1969. Hydrolysis of α-rotunol 3 with 10% sulfuric acid afforded （+）-5α-hydroxy-isopterocarpolone （1）. The structures of all the compounds were confirmed by IR, MS and NMR spectra.
文摘A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.
文摘14-Noreudesma-4,11-dien-3,9-diones′ analogues were treated with DDQ in dioxane and afforded the rearranged aromatic products. The similar compounds to eudesma-4,11-dien-3,9-diones had no reaction. 9-Actoxy-14-noreudesma-4,11-dien-3-ones, 9-actoxy-eudesma-4,11-dien-3-ones and their analogues yielded the normal 1,2-dehydro-products. The mechanism of the rearrangement was discussed.
文摘The selective epoxidation of 3,3-(1,2-ethanediyl-bisoxy)-5(10),9(11)-estradiene-17-α-(1-propynyl)-17-β-ol with Fe(Ⅱ)Pc/PhIO was investigated at 25 ℃? atmospheric pressure. With a molar ratio of Fe(Ⅱ)Pc∶compound(I)∶PhIO at 6.25∶50∶120, the conversion reaches 100%. The overall yield of the products 5α, 10α-epoxide(2) and 5β, 10β-epoxide(3)is 60%, and the molar ratio of 2 to 3 is {8.39∶}1. The product 5α, 10α-epoxide is identified by melting point and HPLC.
