Diethyl cyclobutane-1,1-dicarboxylate

Phase-transfer conditions are used in the synthesis of cyclobutane-1,1-dicarboxylic acid (13). The pivotal step in this procedure is the initial ring formation to give the intermediate diethyl cyclobutane-1,1-dicarboxylate, which then undergoes subsequent acidic saponification to afford 13. albeit in a meager 23% yield.23 24... 

Decarboxylation can be accompanied by hydrolysis in a one-pot reaction as in the formation of cyclobutanecarboxylic acid from diethyl cyclobutane-1,1-dicarboxylate.4... 

Alkylation of malonic ester. This alkylation can be done with a solution of sodium ethoxide in ethanol and requires one mole of reagent per alkyl group introduced. An example is Perkin s synthesis of diethyl cyclobutane-1,1-dicarboxylate by alkylation with triraethylene chlorobromide. When trimethylene dibromide was... 

Alkylation of malonic ester with an equimolar ponion of ethylene bromide or trimethylene bromide produces ring closure to give diethyl esters of 1,1-cyclopropane- and 1,1-cyclobutane-dicarboxylic acids, respectively. Five- and six-membered rings also have been formed in this manner. ... 

Deprotonation of methylene groups containing two electron-withdrawing alkoxycarbonyl groups with an appropriate base easily converts them into their corresponding enolate anions. These enolate anions are able to attack carbon electrophiles to form new C —C bonds. One of the important applications of this reaction is to construct small carbocyclic rings, in particular cyclobutanes. For example, intermolecular condensation of l,3-dibromo-2,2-dimethylpropane (1) and the dipotassium salt of diethyl malonate (2) gives diethyl 3,3-dimethylcyclobutane-l,l-dicarboxylate (3).18... 

High yields of cyclobutane derivatives are obtained from the bis-p-toluene-sulfonates of 1,3-diols, as is shown by the synthesis of diethyl dispiro[3.1.4.1 ]-undecane-2,2-dicarboxylate from 2,2-spiro [3,4]octanebis(methyl /7-toluene-sulfonate) and ethyl malonate (warming with sodium in xylene) 386... 

C10H16O4 cyclobutane-1,1-dicarboxylic acid diethyl ester 3779-29-1... 

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