5α,11-二羟基-2-氧代桉烷-3-烯的全合成

5α，11-二羟基-2-氧代桉烷-3-(5α-Hydroxy—isopterocarpolone，1)是由贾忠建等于1996年从中药南牡蒿中首次分离得到的一种桉烷型倍半萜类天然产物．桉烷型倍半萜类化合物广泛分布于天然植物中，具有较好的昆虫拒食、抑制细胞繁殖和植物生长调节等多种生理活性．天然产物1的合成研究尚未见报道．     

ααTwo new eudesmane sesquiterpenes from Lactuca sativa var. anagustata L

Two new eudesmane sesquiterpene lactones were isolated from the stalk of Lactuca sativa var.anagustata L and their structureswere elucidated by means of spectroscopic methods,including 2D NMR(~1H-~1H COSY,HMBC and NOESY) as 1β-O-β-D-glucopyranosyl-4α-hydroxyl-5α,6β,11βH-eudesma-12,6α-olide(1) and 1β-hydroxyl-15-O-(p-methoxyphenylacetyl)-5α,6β,11βH-eudesma-3-en-12,6α-olide(2).     

9-氧代桉烷-4-烯-3-酮类似物的DDQ脱氢重排反应机理研究

我们在研究 9-氧代桉烷 - 4-烯 - 3 -酮类化合物的 2 ,3 -二氯 - 5 ,6 -二腈基 - 1 ,4-苯醌 (DDQ)脱氢反应时[1] ,发现 1 4-降桉烷 - 4,1 1 -二烯 - 3 ,9-二酮及其 1 0 - Epimer在 DDQ脱氢条件下发生迁移重排反应 ,生成酚类化合物 .反应式如下 :DDQ脱氢反应已被详细研究 ,并被广泛地用于有机合成中 [2～ 5] ,但这种脱氢重排反应尚未见文献报道 .为了深入研究该反应 ,提出可能的重排机理 .我们参照文献 [6～ 1 0 ]方法 ,用 MVK和 EVK与相应的 2 -甲基 - 1 ,3 -二酮进行 Robinson成环反应 ,合成了一系列具有类似结构的化合物 ,并与 DD…     

A novel approach for introduction of C-1 oxygenated group on decalin skeleton: first asymmetric total synthesis of 1α,6α-dihydroxy-eudesm-3-ene

This paper describes a novel approach for introduction of C-1 hydroxy on decalin ring system starting from (−)-carvone. Utilizing the substrate controlled Mukaiyama aldol reaction and alkaline cyclization as key steps, the C-1 oxygenated decalin eudesmane skeleton 2′ and its four isomers were synthesized efficiently. What's more, X-ray structural analysis confirmed sufficiently that something was wrong about the structure of natural product: 1β,6β-dihydroxy-7-epi-eudesm-3-ene as reported by the literature.     

Two new eudesmane derivatives from Verbesina virginica

<正>Two new eudesmane derivatives were isolated from the leaves and flowers of Verbesina virginica,along with the known 6-O-β-E -p-coumaroyl-4α-hydroxyeudesmane(1).Their structures were determined as 6-O-β-Z-p-coumaroyl-4α-hydroxyeudesmane(2) and 6-O-α-E-p-coumaroyl-1β-4α-dihydroxyeudesmane(3) by spectroscopic methods.     

Terpenoids from Roots of Chloranthus spicatus

Five new terpenoids, including four eudesmane‐type sesquiterpenoids, 1 – 4 , and one labdane‐type diterpenoid, 6 , together with ten known compounds, were isolated from the roots of Chloranthus spicatus. The structures and their relative configurations were mainly established by 1D‐ and 2D‐NMR spectra, and MS experiments.     

New Sesquiterpenes from the Flowers of Chrysanthemum indicum L.

Two new guaianolides (=guaianolactones), chrysanthguaianolactone A and B ( 1 and 2 , resp.), and one new eudesmane sesquiterpene, chrysanthemdiol A ( 6 ), together with seven known sesquiterpenes were isolated from the flowers of Chrysanthemum indicum L. Their structures were elucidated on the basis of spectroscopic evidence.     

A New Lignan and two Eudesmanes from Lepidozia vitrea

A new lignan, 1 , was isolated from Lepidozia vitrea, together with two known eudesmane terpenoids, 2 and 3 , as well as 7,8‐dihydroxycoumarin ( 4 ). Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR as well as MS analyses.     

Sesquiterpenes from the Roots of Ligularia duciformis

Two new sesquiterpenes named liguducin-A ( 1 ) and -B ( 4 ) were isolated from a Chinese medicinal plant, the dried roots of Ligularia duciformis, together with four known sesquiterpenes, 4α, 10β-dihydroxy-1β,5α-H-guai-6-ene ( 2 ), 4α-hydroxy-1β,5α,11α-H-guai-9-en-12,8α-olide ( 3 ), 1β-hydroxyeudesm-4,11-dien-3-one ( 5 ) and 1β,6α-dihydroxyeudesm-4(15)-ene ( 6 ). On the basis of the spectral evidence, their structures were determined.     

Senedensiscins A–F: six new eudesmane sesquiterpenoid glucosides from Senecio densiserratus

Six new highly oxygenated eudesmane sesquiterpenoid glucosides, senedensiscins A–F (1–6), were isolated from the aerial parts of Senecio densiserratus. Their structures with the absolute configurations were established on the basis of spectroscopic analyses and chemical methods. These compounds represent an unprecedented type of sesquiterpenoid glucoside with the angeloyl group directly connected to the glucosyl moiety and their cytotoxicity was evaluated against the selected human cell lines, HL-60, SMMC-7721, and HeLa.