Anti-Beckwith stereoselectivity in amidyl radical cyclisations: Bu3SnH-mediated 5-exo-trig acyl mode cyclisation of 2-substituted pent-4-enamide radicals
摘要:
2-Substituted amidyl radicals derived from 8a-d and 9a-d undergo acyl mode 5-exo-trig cyclisation to give 3,5-trans pyrrolidinones 11a-d and 14a-d as the major products in low diastereoselectivity (de = 9-36%). The steric nature of the nitrogen substituent attached to the amidyl radical does not have a significant effect on selectivity. The stereochemical outcome is opposite to that expected based upon applying the Beckwith rule. (C) 2013 Elsevier Ltd. All rights reserved.
Tethered Aminohydroxylation (TA) Reaction of Amides
作者:Timothy J. Donohoe、Cedric K. A. Callens、Amber L. Thompson
DOI:10.1021/ol900631y
日期:2009.6.4
The first examples of amide-tethered aminohydroxylationreactions, catalyzed by osmium, showing that the use of N−O-based reoxidants are essential for success, are reported. The system that is described is compatible with a variety of different alkene substitution patterns and ring sizes and works with low loadings in both cyclic and acyclic systems. The levels of diastereoselectivity that were observed
Compounds and methods of using said compounds singly or in combination with additional agents and compositions of said compounds for the treatment of cancer are disclosed Formula (I)
Compounds of Formula (I), methods of using said compounds singly or in combination with additional agents and compositions of said compounds for the treatment of cancer are disclosed.
Isolation, identification and determination of the absolute configuration of Fischerellin B. A new algicide from the freshwater cyanobacterium Fischerella muscicola (Thuret)
作者:Ulrich Papke、Elisabeth M. Gross、Wittko Francke
DOI:10.1016/s0040-4039(96)02284-8
日期:1997.1
A new 2-pyrrolidinone with a polyunsaturated side chain has been identified from the cyanobacterium Fischerella muscicola (Thuret). Its structure was elucidated by UV, NMR and mass spectroscopy. Derivatisation of the natural product and stereocontrolled synthesis of the derivative allowed the determination of the absolute configuration by means of chiral gas chromatography. The new compound, fischerellin B, shows algicidal properties. Copyright (C) 1996 Elsevier Science Ltd