描述了子叶素 A 的收敛对映选择性全合成。通过我们实验室开发的催化不对称分子内环丙烷化制备的 A 环片段和由已知手性化合物通过修饰的酰基自由基环化制备的 C 环片段通过 Utimoto 偶联反应成功组装。通过钯介导的环化有效地构建了子叶素 A 的强大碳环八元环。支架中的所有羟基都被立体选择性地引入,并开发了一种改良的还原剂 Me4NBH(O2CiPr)3。糖部分片段是通过三个连续的碳氧键形成反应制备的,糖基化是使用万的方案完成的。
Diastereomerically and Enantiomerically Pure 2,3-Disubstituted Pyrrolidines from 2,3-Aziridin-1-ols Using a Sulfoxonium Ylide: A One-Carbon Homologative Relay Ring Expansion
作者:Jennifer M. Schomaker、Somnath Bhattacharjee、Jun Yan、Babak Borhan
DOI:10.1021/ja065833p
日期:2007.2.1
An ylide-based aza-Payne rearrangement of 2,3-aziridin-1-ols leads to an efficient process for the preparation of pyrrolidines. The aza-Payne rearrangement under basic reaction conditions favors the formation of epoxy amines. Subsequent nucleophilic attack of the epoxide by the ylide yields a bis-anion, which upon a 5-exo-tet ring-closure yields the desired pyrrolidine, thus completing the relay of
Synthesis of N-heterocycles, beta-amino acids, and allyl amines via aza-payne mediated reaction of ylides and hydroxy aziridines
申请人:Borhan Babak
公开号:US20090012120A1
公开(公告)日:2009-01-08
An ylide-based aza-Payne rearrangement of 2,3-aziridin-
1
-ols leads to an efficient process for the preparation of pyrrolidines. The aza-Payne rearrangement under the basic reaction conditions favors the formation of epoxy amines. Subsequent nucleophilic attack of the epoxide by the ylide yields a bis-anion, which upon a 5-exo-tet ring closure yields the desired pyrrolidine, thus completing the relay of the 3-membered the 5-membered nitrogen containing ring system. This process takes place with complete transfer of stereochemical fidelity, and can be applied to sterically hindered aziridinols.
Stereoselective Total Synthesis of Natural (S)-Bakuchiol and Its Enantiomer
作者:Xiao-Long Du、Hong-Li Chen、Hui-Jin Feng、Yuan-Chao Li
DOI:10.1002/hlca.200890041
日期:2008.2
A practical stereoselectivesynthesis of (S)-bakuchiol (1) and its enantiomer is reported. The important intermediate, (R)-configured β-siloxy aldehyde 5, was obtained in three steps from the easily available material geraniol (2) via the key step of Yamamoto's rearrangement of epoxy silyl ethers. (S)-Bakuchiol (1) and its enantiomer, (R)-bakuchiol (17), were finally obtained in different synthetic
Enantiocontrolled Total Synthesis of (−)-Retigeranic Acid A
作者:Xiaoming Chen、Weidong Yao、Hufeng Zheng、Hongyu Wang、Pan-Pan Zhou、Dao-Yong Zhu、Shao-Hua Wang
DOI:10.1021/jacs.3c04850
日期:2023.6.28
of (−)-retigeranic acid A has been realized. The key features of the current synthesis include (1) a Pt-catalyzed Conia-ene 5-exo-dig cyclization of enolyne to establish the key quaternary stereochemical center of C-10 (D/E ring), (2) an intramolecular diastereoselective Prins cyclization to construct the trans-hydrindane backbone (A/B ring), and (3) a late-stage intramolecular Fe-mediated hydrogen