Total Syntheses of Naturally Occurring Seimatopolide A and Its Enantiomer from Chiral Pool Starting Materials Using a Bidirectional Strategy
作者:Bernd Schmidt、Oliver Kunz、Monib H. Petersen
DOI:10.1021/jo302359h
日期:2012.12.7
Enantioselective total syntheses of both enantiomers of the recently isolated decanolide natural product seimatopolide A are described. The C2-symmetric building blocks (R,R)-hexa-1,5-diene-3,4-diol (derived from d-mannitol) and itsenantiomer (derived from l-(+)-tartrate) serve as key starting materials, which are elaborated in a bidirectional way using a selective mono-cross-metathesis, regio- and
Palladium-Catalyzed Asymmetric Allylic Alkylation of <i>meso- </i>and <i>dl</i>-1,2-Divinylethylene Carbonate
作者:Barry M. Trost、Aaron Aponick
DOI:10.1021/ja0578348
日期:2006.3.1
The palladium-catalyzedasymmetricallylicalkylation of a 1:1 mixture of dl- and meso-1,2-divinylethylene carbonate is reported. For the first time, both the ionization and nucleophilic addition steps of the catalytic cycle act as enantiodiscriminating steps to give a single product in high enantiomeric excess. The reactions proceed in >98% ee to efficiently generate useful chiral building blocks
据报道,钯催化的 dl-和内消旋 1,2-二乙烯基亚乙基碳酸酯的 1:1 混合物的不对称烯丙基烷基化。这是第一次,催化循环的电离和亲核加成步骤都作为对映体区分步骤,以产生高对映体过量的单一产物。反应以> 98% ee 进行以有效地从丙烯醛生成有用的手性构件。iso-cladospolide B 和 11-epi-iso-cladospolide B 的绝对和相对构型通过全合成验证,解决了文献中的明显差异。
Total synthesis of 1α,25-dihydroxy-2β-(3-hydroxypropoxy)vitamin D3 (ED-71)
作者:Wutong Deng、Qingyin Pu、Yimou Gong、Li Zhou、Jian Sun、Chao Wang
DOI:10.1016/j.tet.2020.131081
日期:2020.4
A convergent method for the synthesis of ED-71 has been developed. Starting from the reported epoxide 5 which could be easily prepared for D-mannitol, ED-71 was synthesized in 11 linear steps with 17% overall yield.
Synthesis of Dihydrofurans and Dihydropyrans with Unsaturated Side Chains Based on Ring Size-Selective Ring-Closing Metathesis
作者:Bernd Schmidt、Stefan Nave
DOI:10.1002/adsc.200600473
日期:2007.1.8
Enantiomerically pure 1,5-hexadiene-3,4-diol, derived from D-mannitol in a few steps, may serve as a starting material for enantiopure dihydropyrans and dihydrofurans bearing an unsaturated side chain which is amenable for further synthetic transformations. The synthesis relies on a ring size-selective ring-closing metathesis reaction of a triene. Most likely, a catalyst-directing effect of an allylic
作者:Hyung Wook Moon、Seung Jong Lee、Seong Hu Park、Se Gyo Jung、In A Jung、Chang Hun Seol、Seung Woo Kim、Seon Mi Lee、Bogonda Gangganna、Seokhwi Park、Kee-Young Lee、Chang-Young Oh、Juyoung Song、Jaehun Jung、Ji Soo Heo、Kang Hee Lee、Hae Sol Kim、Won Taek Lee、Areum Baek、Hyunik Shin
DOI:10.1021/acs.oprd.0c00436
日期:2021.1.15
Industrial-scale synthesis of eldecalcitol is described. AA highly diastereoselective epoxidation of p-methoxybenzyl (PMB) protected dienol at room temperature provides the key epoxide intermediate with a secondary hydroxyl group, which is alkylated with a triflate to set up all of the subunits at the C-1, C-2, and C-3 positions of the A-ring fragment. Selective protecting group manipulation followed