Total Synthesis of Four Isomers of the Proposed Structures of Cryptorigidifoliol K
作者:G. Sudhakar Reddy、Birakishore Padhi、Yada Bharath、Debendra K. Mohapatra
DOI:10.1021/acs.orglett.7b03174
日期:2017.12.15
The first asymmetric convergent totalsynthesis of four isomers of proposedstructures of cryptorigidifoliol K (1a, 1b, 1c, and 1d) has been achieved from commercially available starting materials. The key steps in this synthesis involve tandem isomerization followed by a C–O and C–C bond-forming reaction for the construction of trans-2,6-disubstituted dihydropyran, iodolactonization, isomerization
隐秘三叶醇K(1a,1b,1c和1d)的拟议结构的四个异构体的第一个不对称会聚全合成已从商业上可获得的起始原料中获得。该合成的关键步骤包括串联异构化,然后进行C–O和C–C键形成反应,以构建反式-2,6-二取代的二氢吡喃,碘代内酯化,末端烯烃的异构化和交叉复分解反应。来自天然产物的合成隐秘三叶酚K的光谱数据(1 H NMR)存在较大差异,表明天然隐秘三叶酚K的结构需要修正。
CuBr<sub>2</sub>-catalyzed diastereoselective allylation: total synthesis of decytospolides A and B and their C6-epimers
作者:Birakishore Padhi、G. Sudhakar Reddy、N. Arjunreddy Mallampudi、Utkal Mani Choudhury、Debendra K. Mohapatra
DOI:10.1039/c9ob02689d
日期:——
CuBr2-catalyzed diastereoselective allylation of a cyclic hemiacetal with allyltrimethylsilane as a nucleophile has been developed. The protocol offers a cost effective, protecting group tolerant, and operationally simple approach to 2,6-trans-disubstituted tetrahydropyran with excellent diastereoselectivity. Furthermore, the application of this methodology has been demonstrated in the totalsynthesis of decytospolides
Total Synthesis and Structural Revision of Monocillin VII
作者:N. Arjunreddy Mallampudi、Beduru Srinivas、Jithender G. Reddy、Debendra K. Mohapatra
DOI:10.1021/acs.orglett.9b02075
日期:2019.8.2
first asymmetric totalsynthesis of macrolactone monocillin VII and its C-10′ epimer was achieved starting from a known chiral pure epoxide in 16 longest linear sequences. The present synthesis highlights the macrolactone formation involving an alkyne–dicobalt carbonyl complex under De Brabander’s conditions followed by an unexpected regioselective hydration. The asymmetric totalsynthesis resulted in the
Iodine-Catalyzed Highly Diastereoselective Synthesis of<i>trans</i>-2,6-Disubstituted-3,4-Dihydropyrans: Application to Concise Construction of C28-C37 Bicyclic Core of (+)-Sorangicin A
作者:Debendra K. Mohapatra、Pragna P. Das、Manas Ranjan Pattanayak、J. S. Yadav
DOI:10.1002/chem.200902999
日期:2010.2.15
A novel iodine‐catalyzed highlydiastereoselectivesynthesis of trans‐2,6‐disubstituted‐3,4‐dihydropyrans have been achieved from δ‐hydroxy α,β‐unsaturated aldehydes by treating with allyltrimethyl silane in THF at room temperature with good to excellent yields. This methodology has been successfully implemented for a concise asymmetric synthesis of C28–C37 dioxabicyclo[3.2.1]octane ring system of