112698-13-2Relevant academic research and scientific papers
2-Alkoxy-3-oxoalkyl-tetrahydropyrans and -tetrahydrofurans: versatile intermediates in heterocyclic synthesis
Duhamel, Pierre,Deyine, Abdallah,Dujardin, Gilles,Ple, Gerard,Poirier, Jean-Merie
, p. 2103 - 2114 (2007/10/02)
A new Lewis acid-catalysed Michael-type addition of heterocyclic enol ethers to hemiacetal vinylogues 1 or to enones in the presence of a hydroxylic compounds is described.The 1,5-keto acetal 3 so obtained have been studied with a view to synthetic applications.Acidic hydrolysis of compound 3 leads in most cases to annulation products 9 in a stereocontrolled manner.Organometallic addition, hydride reduction or reductive amination of 1,5-keto acetals 3 afford, in good yields, the hydroxy acetals 12 (and cyclisation products 13) and amino acetals 18, respectively.Acidic treatment of these compounds gave access to oxa- and aza-annulation products 13, 17 and 19 by an efficient kinetically controlled heterocyclisation process.These products can be obtained with high cis-junction selectivities as established by NMR spectroscopy and confirmed by equilibration studies.
REACTION DES VINYLOGUES D'HEMIACETALS ET DE LEURS EQUIVALENTS SYNTHETIQUES SUR LES ETHERS D'ENOLS HETEROCYCLIQUES
Poirier, Jean-Marie,Dujardin, Gilles
, p. 3337 - 3340 (2007/10/02)
We describe the reaction of hemiacetal vinylogs 2 or their synthetic equivalent with cyclic enol ethers 1 yielding ketoacetals 3.Acidic treatment of these compounds leads to bicyclic heterocycles 8 or enone aldehyde 12 depending on the nature of substituents R1.
