DBU-Catalyzed Deconjugation of 7-Substituted 3,4-Didehydro-2-oxepanones. Deuterium Incorporation, Significance of the Imine Double Bond, and Application to the Synthesis of a Key Pharmacophore
摘要:
7-Substituted 3,4-Didehydro-2-oxepanones are conveniently deconjugated to the 4,5-didehydro derivatives by DBU. The isomerization of 7-benzyl-substituted 2-oxepanones proceeds to the extent of 90% over the initial 3 h; the concentration falls gradually thereafter to achieve, in 25 h, a 3:2 equilibrium in favor of deconjugation. Such an equilibrium does not exist for the 7-methyl and the 7-(2-phenethyl) derivatives. The significance of the imine double bond in DBU has been explored. The isomerization in CDCl3 causes deuterium incorporation at positions 3 and 5 of the 2-oxepanones examined and at position 6 of DBU. The mechanistic rationales for these deuterium incorporations are advanced. The transformation of 7-benzyl-3,4-didehydro-2-oxepanone into a bicyclo[3.3.0] skeleton that is present in a diverse class of biologically active natural products is described as a possible potential use of the present deconjugation methodology.
Rearrangement of suitably constituted aryl, alkyl, or vinyl radicals by acyl or cyano group migration
作者:Athelstan L. J. Beckwith、D. M. O'Shea、Steven W. Westwood
DOI:10.1021/ja00216a033
日期:1988.4
Transposition des bromo-2 benzenepropionates d'ethyle, substitues en α par un groupe acetyl ou cyano, en acetyl-2 et cyano-2 benzenepropionate d'ethyle. Synthese d'oxo-3 cyclanecarboxylates d'alkyle a partir de β-cetoesters; par exemple l'iodomethyl-2 oxo-2 cyclopentanecarboxylate d'ethyle conduit a l'oxo-3 cyclohexanecarboxylate d'ethyle
Transposition des bromo-2 benzopropionates d'ethyle, substitues en α par un groupe acetyl ou cyano, en acetyl-2 et cyano-2 benzopropionate d'ethyle。合成这些 d'oxo-3 cyclanecarboxylates d'alkyle a partir de β-cetoesters; 例如,l'iodomethyl-2 oxo-2 cyclopentanecarboxylate d'ethyle 导管 a l'oxo-3 cyclohexcarboxylate d'ethyle
Ring Expansion of Cyclic β-Amino Alcohols Induced by Diethylaminosulfur Trifluoride: Synthesis of Cyclic Amines with a Tertiary Fluorine at C3
As the replacement of a hydrogen atom by a fluorine atom in a compound can have an important impact on its biological properties, the development of methods allowing the introduction of a fluorine atom is of great importance. The scope and limitations of the ringexpansion of cyclic 2-hydroxymethyl amines induced by diethylaminosulfur trifluoride (DAST) to produce cyclic β-fluoro amines was studied
Systematic SAR optimization of the GPR119 agonist lead 1, derived from an internal HTS campaign, led to compound 29. Compound 29 displays significantly improved in vitro activity and oral exposure, leading to GLP1 elevation in acutely dosed mice and reduced glucose excursion in an OGTT study in rats at doses >= 10 mg/kg. (C) 2014 Elsevier Ltd. All rights reserved.
Matsumoto, Kazutsugu; Tsutsumi, Seiji; Ihori, Tamiko, Journal of the American Chemical Society, 1990, vol. 112, # 26, p. 9614 - 9619