19946-69-1Relevant academic research and scientific papers
Formation of four- to six-membered carbocycles by tandem brook rearrangement-intramolecular Michael reaction
Takeda, Kei,Tanaka, Tadashi
, p. 705 - 708 (1999)
A tandem Brook rearrangement-intramolecular Michael reaction has been developed as a synthetic route to functionalized carbocycles. Acylsilanes, tethered by a two-, three-, or four-carbon chain to an acrylate Michael acceptor, have been prepared and used as the cyclization substrates. Treatment of these compounds with PhLi or LiP(O)(OMe)2 at temperatures below 0°C results in the formation of four- to six-membered carbocycles in good yields.
Electroreductive coupling of aromatic ketones, aldehydes, and aldimines with α,β-unsaturated esters: Synthesis of 5-aryl substituted γ-butyrolactones and lactams
Kise, Naoki,Hamada, Yusuke,Sakurai, Toshihiko
, p. 1143 - 1156 (2017/02/18)
The electroreductive intermolecular coupling of aromatic ketones and aldehydes with α,β-unsaturated esters in the presence of TMSCl gave the adducts as γ-trimethylsiloxy esters. The detrimethylsilylation of the adducts with TBAF afforded 5-aryl substituted γ-butyrolactones. The electroreductive coupling of N-(4-methoxyphenyl)-1-arylmethaneimines with methyl acrylate in the presence of TMSCl gave the adducts as methyl 4-aryl-4-((4-methoxyphenyl)amino)butanoates. The adducts were transformed to 5-aryl-γ-butyrolactams by cyclization with NaH and subsequent oxidation with CAN. (±)-Norcotinine was prepared from nicotinaldehyde by this method. The electroreductive coupling of aromatic ketones and aldimines with acrylonitrile in the presence of TMSCl gave 4-aryl-4-(trimethylsiloxy)butanenitriles and 4-aryl-4-((4-methoxyphenyl)amino)butanenitriles, respectively.
Electrophile-initiated lactonization of 7-phenytricyclo[4.1.0.0 2,7]heptane-1-carboxylic acid
Razin,Zolotarev
, p. 1710 - 1715 (2007/10/03)
Treatment of 7-phenyltricyclo[4.1.0.02,7]heptane-1-carboxylic acid with benzenesulfenyl chloride, mercury acetate, and hydrogen chloride leads to cleavage of the central C-C bond in the bicyclobutane fragment and heterocyclization to substitute
Synthesis of 1-Substituted cis-Bicyclooctanones through Cycloadditions of Dichloroketene to Alkenes. Structural Characterization of Cycloadducts by Oxa-Ring Expansion
Jeffs, Peter W.,Molina, Gerado,Cass, Malcom W.,Cortese, Nicholas A.
, p. 3871 - 3875 (2007/10/02)
The cycloaddition of dichloroketene to a series of 1-substituted cyclohexanes is shown to proceed in a highly regio- and stereospecific manner.The structures of the cycloadducts were determined by reductive dechlorination to the cyclobutanones, and the structures and stereochemistry of the latter as cis-bicyclooctan-7-ones (4) were established by an oxa-ring expansion to the corresponding cis-octahydrobenzofuran-2-ones (6).The structures of the lactones 6 were established by 1H and 13C NMR studies which further indicated that these compounds exist in conformation 6a rather than 6b.The success of the regio- and stereospecific cycloaddition of dichloroketene to the 1-substitutd cyclohexenes discussed is found to be critically dependent on utilizing the zinc dehalogenation procedure for its in situ generation.Additional examples of the cycloaddition of dichloroketene to indene, 1,4,-dihydronaphthalene and 1,2-dihydronaphthalene is also presented.
