The use of 2-(1-alkoxyalkylidene)-1,3-dicarbonyl compounds in organic synthesis

Haloacetylated Enol Ethers: a Way Out for the Regioselective Synthesis of Biologically Active Heterocycles

“…Enol ethers belong to a class of activated alkenes that are easily acylated when highly electron‐deficient acylating agents (e. g. trichloroacetyl chloride, trifluoroacetic anhydride, ethyl oxalyl chloride, etc.) are used [14,15] . Scheme 2 outlines the preparation of these haloacetylated enol ethers, starting from methyl ketones 1 , which are reacted with trimethyl orthoformate to furnish acetals 2 .…”

Synthesis of Fused Pyridine Carboxylates by Reaction of β-Alkoxyvinyl Glyoxylates with Amino Heterocycles

“…36 It is also well known that simplest 1,3-dicarbonyl compounds, for example, bearing an aldehyde group, have limited stability due to their extremely high electrophilicity. [37][38][39] Thus, -alkoxyvinyl carbonyl compounds were developed as synthetic equivalents of such classical CCC bis-electrophiles. Besides increased stability and possibility for preparation of the simplest representatives, improved regioselectivity and increased yields of the condensation products were observed with these building blocks.…”

Synthesis of 4-(1,3,5-Thiadiazinan-2-ylidene)-2-(3,4- dihydro-2H-1,3,5-thiadiazin-6-yl)pent-2-enedinitriles

“…These results can be explained by the mechanism presented in Scheme 3. First, an SNVin vinyl nucleophilic substitution reaction takes place [21][22][23] Further investigation of the reaction of cyanothioacetamide with ethoxymethylene malonate in the presence of triethylamine and N-methylmorpholine allowed us to conclude that: (1) in the case of N-methylmorpholine under the conditions described earlier [19]; pentadiethiolates 5 were not isolated; (2) replacement of N-methylmorpholine to triethylamine favors the formation of compound 5 under short-term heating of a mixture; (3) the content of product 5 in the mixture does not exceed 10-15 mol% (according to 1 H NMR); (4) analytically pure triethylammonium 3-cyano-5-ethoxycarbonyl-6-oxo-1Н-pyridine-2-thiolate 1 can be prepared by reaction of cyanothioacetamide and ethoxymethylene malonate in acetonic solution at the room temperature; (5) a longer heating neither favors the formation of compound 5, nor leads to an increase in the yields of thiolates 1 or 2, but leads to a noticeable resinification of the reaction mixture, possibly due to further intramolecular cyclizations of compounds 5 or 7, or self-condensation of cyanothioacetamide, which occurs under basic conditions [29,30]. It should also be noted that, contrary to expectations, neither pure thiolate 1 nor thiolate 2 give any Mannich-type products under the conditions stated; a noticeable resinification of reaction mass was observed during the synthesis.…”