Préparation des organozinciques dérivés de l'α-bromométhyl acrylate d'éthyle et de ses homologues
作者:Najat El Alami、Chantal Belaud、Jean Villiéras
DOI:10.1016/0022-328x(88)80333-4
日期:1988.6
α-bromoalkyl acrylates (aliphatic and alicyclic) results in high yields when carried out on 30 mesh activated granular zinc, between 14 and 20°C in ethereal solvents (THF, DME, ether). Under these conditions duplication can be minimized (5–15%) especially with t-butyl acrylates. These α-functional allylic organozinc derivatives have been characterized by hydrolysis and coupling with benzaldehyde.
The asymmetric synthesis of α-methylene-γ-butyrolactones via a tandem allylboration/lactonization approach was achieved using a chiral N,N′-dioxide/AlIII complex. The kinetic resolution of the allylboration intermediate via asymmetric lactonization was found to be a key aspect responsible for the success of this transformation. Stereodivergent syntheses and total syntheses of eupomatilones 2, 5 and
使用手性N , N ' -二氧化物/Al III络合物,通过串联烯丙基硼化/内酯化方法实现了 α-亚甲基-γ-丁内酯的不对称合成。发现烯丙基硼化中间体通过不对称内酯化的动力学拆分是该转化成功的关键因素。对Eupomatilones 2、5和6的立体发散合成和全合成证明了其合成实用性。
LAMBERT, FRANCOIS;KIRSCHLEGER, BERNARD;VILLIERAS, JEAN, J. ORGANOMET. CHEM., 406,(1991) N-2, C. 71-86
作者:LAMBERT, FRANCOIS、KIRSCHLEGER, BERNARD、VILLIERAS, JEAN
sesbanimides 1 and 2, potent antitumor alkaloids, were performed starting from the synthetic intermediates of our first total synthesis of 1 and 2. The C-ring systems 14a–d were synthesized by applying the previously explored novel Reformatsky reaction to various aldehydes. The opticallyactive BC-ring systems 20 and 21 having the same absoluteconfigurations as those of 1 and 2, were derived from (−)-2,4-O-methylene
从我们第一次全合成 1 和 2 的合成中间体开始,制备了有效抗肿瘤生物碱 sesbanimides 1 和 2 的一些 AB 环系统 5 和 8。 C 环系统 14a-d 是通过应用合成的之前探索了对各种醛的新型 Reformatsky 反应。具有与1和2的绝对构型相同的绝对构型的旋光BC-环系统20和21源自作为B-环合成子的(-)-2,4-O-亚甲基D-山梨糖醇(15)。由于所有这些化合物 5、8、14a-d、20 和 21 以及先前合成的 AB 环系统 3 对 P388 鼠白血病没有显着的体外细胞毒性,因此很明显 1 和 2 表现出显着的抗肿瘤活性A 型环和 C 型环的配合。