Ethyl mesoxalate

Condensation of hydroxy aldehydes with ethyl glyoxylate or ethyl mesoxalate. 

Condensation of Hydroxy Aldehydes with Ethyl Glyoxylate or Ethyl Mesoxalate... 

Furthermore it has been shown that ethyl mesoxalate can be used instead... 

The alkene 1-decene (24) was poorly reactive in the carbonyl-ene reaction with ethyl mesoxalate and required a temperature up to 170 °C for a very long time (5 h) [42]. When performed in a homogeneous liquid medium at the same temperature but under the action of MW irradiation the reaction gave a similar result. Reaction time was appreciably shortened by use of GS/MW coupling [30]. Thus, irradiation at 60 W for only 10 min led to the ene adduct 25 in 50% yield (Scheme 7.2). Under these conditions a maximum temperature of 230 °C was measured. To obtain the same yield with conventional heating at 170 °C reaction for 1 h is required. The stereoselectivity of the reaction was not related to the mode of heating. A higher con-... 

Pinene (26), a more reactive ene than 24, reacted with ethyl mesoxalate under CC14 reflux in 90% yield after 5 h conventional or MW heating [42]. The reaction supported on graphite occurred in only 2x1 min of MW irradiation with an incident power of 60 W. The adduct 27 was obtained in 67% isolated yield (Scheme 7.3) [30]. This yield was obtained after 2 h of reaction under CC14 reflux. 

The first fraction consists mainly of water, a little ethyl acetate, and some ethyl oxomalonate which recombines with the water to form ethyl mesoxalate. When the pressure has dropped to 45 mm. and the temperature has risen to 1 xo°, the receiver is... 

The [4 + 2] cycloaddition of dienes 1 with ethyl mesoxalate (11) gives a mixture of two adducts 12 and 13 which differ in the configuration at C-l. Depending on the chiral auxiliary used, adducts with predominantly S or R configuration at C-l can be obtained. 

Although the orientation of the products 28 and 29 has not been confirmed, they are consistent with the observation that ethyl mesoxalate... 

Ethyl mesoxalate (Et02CC0C02Et) reacts with 3,4-diaminopyridine in ethanol to give a mixture in which the expected 2-oxo compound 39... 

The pyrido[3,2-rf]pyrimidine (135) was prepared by condensation of the pyrimidinedione (133) with an a-oxoester such as methyl pyruvate or ethyl mesoxalate, or with diethyl oxalate, in the presence of a base. Presumably the reaction involves initial condensation to give the imine (134) as shown in Scheme 29 (57CB728) (cf. Section VIII). 

Another wing pterin was found to be an isomer of xanthopterin and given the name isoxanthopterini. The synthesis of this colorless pterin was accomplished by condensation of ethyl mesoxalate with 2,4,5-triamino-6-hy-droxypyrimidine followed by decarboxylation of the intermediate as indicated in the above equations . A small amount of xanthopterin-7-carboxylic acid was also formed in the initial step, but in the presence of sulfuric acid, the products consist of 42% xanthopterin-7-carboxylic acid and 29% iso-xanthopterin-6-carboxyhc acid. Xanthopterincarboxylic add could not be decarboxylated but conversion to a dihydro derivative, decarboxylation of the dihydro derivative, and catalytic oxidation gave xanthopterin. Leuco-pterin can be reduced to a dihydroxanthopterin and reoxidized to xanthopterin. On the basis of absorption spectra of related derivatives, leucopterin and isoxanthopterin appear to have structures in which all of the hydroxyl groups indicated are in the lactam configuration . 

Ethyl-5-isopentyl-2,4,6(lH,3H,5/f)-pyrimidinetrione Ethyl isopropyl ketone Ethyl isopropylmalonate Ethyl isovalerate Ethyl linoleate Ethyl linolenate AT-Ethylmaleimide Ethyl mercaptan Ethyl mesoxalate Ethyl 4-methoxyphenyl ketone Ethyl 4-methylcaproate Af-Ethyl-Af-methylethanamine Ethyl 3-methyl-3-phenylglycidate Af-Ethyl-2-methyl-2-propen-l-amine Ethyl nicotinate Af-Ethyl-Af-nitroethanamine 2 -Ethyl-2 - [(nitrooxy)methyl] -1,3-propanediol, dinitrate Ethyl octadecanoate Ethyl cis-9-octadecenoate Ethyl oenanthate Ethyl oxalyl chloride Ethyloxirane... 

Ethyl mesoxalate 3474 Eucarvone 10529 Furo [3,4-b] pyridine-5,7-dione 9344... 

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