Total Synthesis of (−)-Chromodorolide B By a Computationally-Guided Radical Addition/Cyclization/Fragmentation Cascade
作者:Daniel J. Tao、Yuriy Slutskyy、Mikko Muuronen、Alexander Le、Philipp Kohler、Larry E. Overman
DOI:10.1021/jacs.7b13799
日期:2018.2.28
The first total synthesis of a chromodorolide marine diterpenoid is described. The core of the diterpenoid is constructed by a bimolecular radical addition/cyclization/fragmentation cascade that unites two complex fragments and forms two C-C bonds and four contiguous stereogenic centers of (-)-chromodorolide B in a single step. This coupling step is initiated by visible-light photocatalytic fragmentation
描述了 chromodorolide 海洋二萜的首次全合成。二萜的核心是通过双分子自由基加成/环化/断裂级联反应构建的,该级联反应将两个复杂片段结合在一起,并在一个步骤中形成两个 CC 键和 (-)-chromodorolide B 的四个连续立体中心。该偶联步骤由氧化还原活性酯的可见光光催化裂解引发,可在铱或不太贵的富电子二氰基苯光催化剂存在下完成,并使用等摩尔量的两个加成物。计算研究指导了合成的这一核心步骤的发展,并提供了对观察到的立体选择性起源的深入了解。
Synthesis of enantiomerically pure spiro-cyclopropane derivatives containing multichiral centers
作者:Hui Huang、Qinghua Chen
DOI:10.1016/s0957-4166(98)00416-9
日期:1998.12
A novel chiral source, 5-(R)-[(1R,2S,5R)-(−)-menthyloxy]-3-bromo-2(5H)-furanone (5a), was obtained in 46% yield with d.e.≥98% from the epimeric mixture of 5-(l-menthyloxy)-3-bromo-2(5H)-furanone (5a+5b) obtained via the bromination of an epimeric mixture of 5-(l-menthyloxy)-2(5H)-furanone (3a+3b) followed by the elimination of hydrogen bromide. The asymmetricreaction of 5a with a nucleophilic alcohol
以46%的收率获得了新型手性来源5-(R)-[(1 R,2 S,5 R)-(-)-薄荷基氧基] -3-溴-2(5H)-呋喃酮(5a)与de≥98%由5-(的差向异构体混合物升-menthyloxy)-3-溴-2(5H) -呋喃酮(图5a + 5b中)经由5-(的差向异构体混合物的溴化得到的升-menthyloxy) - 2(5H)-呋喃酮(3a + 3b),然后除去溴化氢。5a与亲核醇的不对称反应提供了对映体纯的螺-环丙烷衍生物,其中包含四个立体异构中心,即9a –9e,产率50-68%,de≥98%。对映体纯的化合物9a - 9e是根据其分析数据和光谱数据(例如[α] D 20,UV,IR,1 H NMR,13 C NMR,MS和元素分析)鉴定的。通过X射线晶体学确定手性螺-环丙烷化合物9a的绝对构型。
A valuable synthetic route to spiro-cyclopropane derivatives containing multiple stereogenic centers
作者:Hui Huang、Qinghua Chen
DOI:10.1016/s0957-4166(99)00123-8
日期:1999.4
corresponding spiro-cyclopropane derivative 8g. Interestingly, reaction of 5a with ethyl bromo- and chloroacetate, in the usual manner, gave the spiro-cyclopropane 8h rather than the expected C-linked derivative. The absolute configuration of the interesting spiro-cyclopropanes 8 was established by X-ray crystallography. These results provide a valuable syntheticroute to some complex molecules containing
Straightforward Synthesis of Isopropylidenediphenylsulfurane and Application to Industrially Viable Stereoselective Synthesis of Deltamethrin Insecticide
作者:A. Krief、Ph. Lecomte、J. P. Demoute、W. Dumont
DOI:10.1055/s-1990-26851
日期:——
We describe three stereoselective syntheses of deltametrin, one of the most potent industrially available insecticides, from γ-alkoxy-α,β-unsaturated carbonyl compounds, isopropyldiphenylsulfonium tetrafluoroborate and potassium tert-butoxide.
Preparation of (1,5) 6,6-dimethyl-4-hydroxy-3-oxabicyclo (3,1,0)
申请人:Roussel Uclaf
公开号:US04769478A1
公开(公告)日:1988-09-06
An improved process for the preparation of compounds of the (1R,4R,5S) or (1S,4S,5R) configuration of the formula ##STR1## wherein Y is selected from the group consisting of hydrogen and the organic residue Z of a chiral alcohol of the formula ZOH is disclosed.