15023-38-8Relevant academic research and scientific papers
Two-carbon homologation of aldehydes and ketones to α,β- unsaturated aldehydes
Petroski, Richard J.,Vermillion, Karl,Cosse, Allard A.
experimental part, p. 5062 - 5078 (2011/08/21)
Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β- unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2- phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the reagent with the starting aldehyde, followed by removal of the dimethylhydrazone protective group with a biphasic mixture of 1 M HCl and petroleum ether. This robust two-step process worked with a variety of aldehydes and ketones. Overall isolated yields of unsaturated aldehyde products ranged from 71% to 86% after the condensation and deprotection steps.
Preparation and deprotection of aldehyde dimethylhydrazones
Petroski, Richard J.
, p. 1727 - 1734 (2007/10/03)
Aldehydes were conveniently protected as dimethylhydrazones by stirring a mixture of the aldehyde, N,N-dimethylhydrazine, anhydrous magnesium sulfate, and dichloromethane at room temperature. Azeotropic removal of water, formed during the course of the reaction, was not required because anhydrous magnesium sulfate functions as a water scavenger. Deprotection of aldehyde dimethylhydrazones was accomplished by stirring a mixture of the aldehyde dimethylhydrazone and aqueous glyoxylic acid at room temperature. The reaction time for the preparation and deprotection of aldehyde dimethylhydrazones varied with the structure of the aldehyde. Copyright Taylor & Francis Group, LLC.
A novel, one-pot synthesis of α-C-cyanohydrazines in the presence of lithium perchlorate/diethylether solution (5.0 M)
Heydari, Akbar,Baharfar, Robabe,Rezaie, Mohsen,Aslanzadeh, Saied M.
, p. 368 - 369 (2007/10/03)
Condensation of N,N-dimethylhydrazine, an aldehyde in lithium perchlorate/diethylether solution (5.0 M) gave N,N-dimethylhydrazone, which were treated with trimethylsilylcyanide to afford α-C-cyanohydrazine. These compounds are important precursors of nitrogen-substituted reagents.
α-Alkylation of α,β-Unsaturated Aldehyde Dimethylhydrazones Accompanied with the Double Bond Migration to β,γ
Yamashita, Masakazu,Matsumiya, Kaoru,Nakano, Ken-ichi
, p. 1759 - 1763 (2007/10/02)
Lithiated α,β-unsaturated aldehyde N,N-dimethylhydrazones reacted with alkyl halides accompanied by double bond migration to give α-alkylated β,γ-unsaturated aldehyde N,N-dimethylhydrazones in satisfactory yields.This reaction was found to be caused at the first step by deprotonation from a γ-carbon atom by lithium diisopropylamide.In the case of hydrazones with two kinds of γ-protons, deprotonation from the less hindered γ-carbon occurred selectively.Using this reaction, a novel sesquiterpene, 2,5,9-trimethyl-2-vinyl-4,8-decadienal, which has a vinyl group at the α-position, was synthesized in a good yield.
