Diverse synthesis of the C ring fragment of bryostatins via Zn/Cu-promoted conjugate addition of α-hydroxy iodide with enone
作者:Zhiwen Chu、Ruiqi Tong、Yufan Yang、Xuanyi Song、Tian bao Hu、Yu Fan、Chen Zhao、Lu Gao、Zhenlei Song
DOI:10.1016/j.cclet.2020.11.039
日期:2021.1
precursors for constructing the C ring of bryostatins, has been developed via a Zn/Cu-promoted conjugate addition of α-hydroxy iodides with enones. The reaction leads to direct formation of the C21-C22 bond and tolerates diverse functionalities at the C17-, C18- and C24-positions. The approach also enables a more concise synthesis of the known C ring intermediate (10 longest linear steps and 14 total
Cation-π Interactions Contribute to Substrate Recognition in γ-Butyrobetaine Hydroxylase Catalysis
作者:Jos J. A. G. Kamps、Amjad Khan、Hwanho Choi、Robert K. Lesniak、Jürgen Brem、Anna M. Rydzik、Michael A. McDonough、Christopher J. Schofield、Timothy D. W. Claridge、Jasmin Mecinović
DOI:10.1002/chem.201503761
日期:2016.1.22
on substrate analogues with P and As substituting for N in the trimethylammonium group show that the analogues are good BBOX substrates, which follow the efficiency trend N(+) >P(+) >As(+). The results reveal that an uncharged carbon analogue of γBB is not a BBOX substrate, thus highlighting the importance of the energetically favorable cation-πinteractions in productive substraterecognition.
Synthesis of Optically Active 5-(<i>tert</i>-Butyldimethylsiloxy)-2-cyclohexenone and Its 6-Substituted Derivatives as Useful Chiral Building Blocks for the Synthesis of Cyclohexane Rings. Syntheses of Carvone, Penienone, and Penihydrone
作者:Georges P-J. Hareau、Masakazu Koiwa、Shinichi Hikichi、Fumie Sato
DOI:10.1021/ja9843122
日期:1999.4.1
Ti(II)-mediated intramolecular nucleophilic acyl substitution reaction and the FeCl3-mediated ring expansion reaction of a 1-hydroxybicyclo[3.1.0]hexane are the key reactions. The enone 1 reacted with higher-order cyanocuprates with excellent diastereoselectivity to afford the trans-addition products, trans-13, in excellent yields. The reaction of 1 with lower-order cyanocuprates proceeded with moderate
A Concise Stereoselective Total Synthesis of Methoxyl Citreochlorols and Their Structural Revisions
作者:Ranganayakulu Sunnapu、Goreti Rajendar
DOI:10.1002/ejoc.202001563
日期:2021.3.19
A concise, highly stereoselective and protecting group free total synthesis of methoxyl citreochlorols was demonstrated. All four stereoisomers were synthesized to establish the absolute stereochemistry of the reported structures and the structures were revised accordingly. An insitu generated silyl iodide promoted ring‐opening iodo esterification of lactones, a direct dichloromethylation of ester
(+)-Negamycin was synthesised employing the highly diastereoselective conjugate addition of lithium (alpha-methylbenzyl)benzylamide in the key step. The synthesis was completed in 13 steps starting from ethyl 4-chloroacetoacetate with an overall yield of 24 %. Copyright (C) 1996 Elsevier Science Ltd