- TiCl4/Et3N-Mediated Condensation of Acetate and Formate Esters: Direct Access to β-Alkoxy- and β-Aryloxyacrylates
-
A methodology to build (E)-β-alkoxy- and (E)-β-aryloxyacrylate moieties from acetate and formate esters promoted by the TiCl4/Et3N system is presented. The reaction is compatible with a broad range of structural skeletons and elapses through an unusual condensation pathway. Taking into account the obtained results, we propose a plausible mechanism involving a bimetallic titanium intermediate for this type of transformation.
- álvarez-Calero, José María,Jorge, Zacarías D.,Massanet, Guillermo M.
-
supporting information
p. 6344 - 6347
(2016/12/23)
-
- Platinum- and gold-catalyzed hydroalkoxylation and tetramerization of propiolate esters
-
PtCl2 was found to efficiently catalyze intermolecular additions of propiolate esters with alcohols. The reaction of propiolate esters and alcohols in the presence of PtCl2 gave (E)-vinyl ethers as the major products at 60 °C, whereas alkyl 3,3-dialkoxypropanoates were predominantly obtained when the reaction temperature was set to 80°C. On the other hand, a novel regioselective tetramerization of propiolate esters catalyzed by AuCl3 under mild conditions afforded 1,2,5,6-tetrasubstituted- cyclooctatetraene (1,2,5,6-COT) in moderate yields.
- Chen, Qian,Zhang, Changyuan,Wen, Chunxiao,Fang, Jin,Du, Zhiyun,Wu, Dongling
-
p. 101 - 105
(2014/08/18)
-
- Catalytic synthesis of 3-alkoxyacrylic acid esters under neat conditions
-
Triethylamine or Ph3P (0.05 eq.) was found to catalyze the addition of alcohols to alkyl propiolates. The reaction occurred much more rapidly without solvent than in solvent. The E/Z ratio was relative to the reaction temperature. Water was fou
- Wang, Junhua,Wang, Honglin,Ren, Hongmin
-
experimental part
p. 980 - 983
(2010/05/18)
-
- METHOD FOR PRODUCING SUBSTITUTED VINYL ETHER DERIVATIVE
-
PROBLEM TO BE SOLVED: To provide a method for producing a substituted vinyl ether derivative by ether exchange from a substituted vinyl ether which has an electron-attracting group as a substituent on a double bond carbon atom to cause the binding site to be electron-deficient. SOLUTION: The method for producing a substituted vinyl ether derivative comprises subjecting a substituted vinyl ether, which has at least one electron-attracting group as a substituent on a carbon atom which forms carbon-carbon double bond, to ether exchange reaction with an alcohol or a phenol in the presence of a catalyst containing a compound of the group 9 and/or 10 metal in the periodic table, wherein the compound has a counter anion, and when the anion is protonated, the proton has an ionization constant (pKa) of 0 or less.
- -
-
Page/Page column 9
(2008/06/13)
-
- Electroorganic Synthesis, 56. Synthesis of Advanced Prostaglandin Precursors by Kolbe Electrolysis, I. - Preparation of (1'R,4'S,3R/S)-3-(cis-4-Acetoxycyclopent-2-enyloxy)-3-ethoxypropionic Acid
-
The key intermediate of a novel synthesis of prostaglandin precursors, (1'R,4'S,3R/S)-3-(cis-4-acetoxycyclopent-2-enyloxy)-3-ethoxypropionic acid (3), is prepared by two different synthetic sequences: In a first strategy transacetalization of ethyl 3,3-diethoxypropionate (6) with (1R,4S)-4-acetoxy-1-hydroxy-2-cyclopentene (7) leads to the formation of the mixed acetal 8.By subsequent hydrolysis and acylation 8 could be converted into acid 3 in six steps in 6percent overall yield.However, the generation of acid 3 by bromoalkoxidation of 3-ethoxyacrylates 13d, e and subsequent electrochemical reduction proved to be more efficient.In this reduction it is possible to debrominate the α-bromo esters 14d, e and to remove the 2-haloethyl ester group in one step.Using this reaction sequence, we could synthesize acid 3 in five steps in 38percent overall yield. - Key Words: Kolbe electrolysis / Radical cyclization / Electrochemical dehalogenation / Prostaglandins
- Weiguny, Jens,Schaefer, Hans J.
-
p. 225 - 234
(2007/10/02)
-
- CHEMISTRY OF ENOL ETHERS. LXXXVIII. CONDENSATION OF THE TETRAETHYLACETAL OF MALONALDEHYDE WITH β-SUBSTITUTED ENOL ALKYL ETHERS
-
The action of β-substituted enol ethers on the tetraethylacetal of malonaldehyde gave the acetals of 1,5- and 1,7-dialdehydes.The nature of the substituent in the enol ether was found to affect the regioselectivity of the reaction: condensation with ethers containig an electron-wthdrawing substituent leads to 1,5-dialdehyde acetals, while condensation with ethers containig a strong electron donor substituent leads to 1,7-dialdehyde acetals.
- Makin, S. M.,Kruglikova, R. I.,Kharitonova, O. V.,Arshava, B. M.
-
p. 1846 - 1849
(2007/10/02)
-
- Ketene Chemistry I. 3,3-Dialkoxypropionates and 3-Alkoxyacrylates. Acid catalysed Self-condensation of Ethyl 3,3-Diethoxypropionate and Ethyl 3-Ethoxyacrylate.
-
The acid catalyzed selfcondensation of ethyl 3,3-diethoxypropionate and ethyl 3-ethoxyacrylate has been studied under various conditions.The products of the reaction include di- and trimeric, open chain structures as well as pyrones and triethyl 1,3,5-benzenetricarboxylate.
- Jacobsen, Niels,Winckelmann, Ib
-
p. 987 - 996
(2007/10/02)
-
- Preparation d'acetals fonctionnels
-
Functional acetals can be prepared either by reaction of functional organomagnesium compounds with the mixed orthoformate C6H5O-CH()C2H5)2 or by reaction of carbonyl compounds with the acetylenic lithium compounds Li-CC-(CH2)n-CH(OC2H5)2 (n=0,1).
- Barbot, Francis,Miginiac, Philippe
-
-