桉烷倍半萜-7(11),8(9)-共轭双烯中间体的合成

二氢沉香呋喃倍半萜多羟基酯(结构如1)是从卫矛科植物中分离提取的主要成分.生物活性试验表明该类物质不仅具有许多重要的生理活性[1～2],而且还具有低毒的杀虫活性[3],有可能研究开发成一类新型的低毒杀虫剂.但是截止目前,有关这类多羟基化合物的合成方法极其复杂,需要近20个反应步骤[4].     

多羟基取代二氢沉香呋喃倍半萜的合成方法

二氢沉香呋喃倍半萜是一类具有杀虫、抑菌等多种活性的天然化合物.由于重要的生物活性和结构的复杂性,从而吸引了有机合成化学家的关注.最近,我们小组从桉烷倍半萜α-(-)-山道年出发,经过NBS促进的四氢呋喃环成环、OsO4双羟基化、环氧化合物的碱重排等一系列官能团转化,合成了七羟基取代的二氢沉香呋喃倍半萜化合物1,进而开拓了一种新颖、简洁的合成多羟基取代二氢沉香呋喃倍半萜的方法,其合成路线如下所示.     

First Synthesis of (+)-2,14-Deoxyalatol from -Santonin

IntroductionAlargenumberofthedihydroagarofuransesquiter-penes,isolatedfromCelastraceaeplantshavebeendemonstratedtoexhibitmanyimportantbiologicalac-tivities,suchascytotoxic,1antitumor,2immunosuppres-sive,3insecticided,4anti-HIVactivities,5etc.Therefore,synthesisofthiskindofcompoundshasbeenattractingthegreatinterestoforganicchemists,andsomemethodshavebeenreported.6Theseapproaches,however,areusuallyapplicabletothosecompoundswiththespecialhydroxylgroupnumberand/orspecialhydroxylsubsti-tutionfash…     

First Synthesis of （＋）-2,14-Deoxyalatol from α-Santonin

A novel and general approach for synthesis of the multi-oxygenated dihydrofuran sesquiterpenes has been developed starting from santonin. The key steps involve: the strategic acid-catalyzed double-bond shifting affording 4, the novel base-promoted epoxide rearrangement of 5 generating two key functionals (the C5-OH and the Δ^7,11 double bond), and the stereoselective cyclization of tetrahydrofuran ring without pre-controlling the stereochemistry of C-7. As an example of this approach, synthesis of ( )-2,14-deoxyalatol was described in detail.