Cyclobutane-1,1-dicarboxylic acid, and

Experiment 7.2 CYCLOBUTANE-1,1-DICARBOXYLIC ACID AND CYCLOBUTANECARBOXYLIC ACID... 

Place 30 g. of cyclobutane-1 1-dicarboxylic acid in a 100 ml. distilling flask, fitted with a thermometer, and connect the side arm to a 60 ml. Claisen flask supported in a funnel so that it can be cooled externally by running water. Heat the distilling flask in a metal bath at 160-170°... 

Decarboxylation reactions of cyclobutanecarboxylic acids appear to pose no particular problems. Cyclobutane-1,1-dicarboxylic acids can usually be decarboxylated thermally at temperatures up to 200 C.1 5> n 340 For example, cyclobutane-1,1,3,3-tetracarboxylic acid was heated to 185 °C at reduced pressure to give a mixture of cis- and frani-cyclobutane-l,3-dicarboxylic acid (l).1 Noteworthy in this reaction is the stereocontrof obtained in the product due to the formation of the anhydride. Generally, decarboxylation will give a mixture of cis- and transacids. The decarboxylation has sometimes been performed in a distillation step.4,5... 

A magnetically stirred mixture of cyclobutane-1,1-dicarboxylic acid (1.6 g, 11.1 mmol), HgO (3.3 g, 15.7 mmol), and Br2 (1.14 mL, 3.55 g, 22.2 mmol) in CH2C12 (40 mL) was heated at reflux for 80 min, cooled in an ice bath, treated with pentane (15 mL), and suction filtered. Following rinsing of the filter cake with pentane, the filtrate was concentrated by simple distillation. Pentane was added, the solids were removed by filtration, and the filtrate was washed with 1 M NaOH and brine prior to drying. The pentane was distilled to leave a residue, which in turn was bulb-to-bulb distilled to give the product yield 1.1 g (46%) bp 80-120 "C (bath)/31 Torr. 

Place 30 g (0.28 mol) of cyclobutane-1,1-dicarboxylic acid in a 100-ml flask fitted with a still-head carrying a thermometer and leading to a cooled receiver flask via a short air condenser. Heat the flask in a Silicone oil bath at 160-170°C until all effervescence ceases. Then raise the temperature of the bath to 210 °C the cyclobutanecarboxylic acid passes over at 191-197 °C. Redistil the acid the pure acid distils at 195-196 °C. The yield of cyclobutanecarboxylic acid (a colourless liquid) is 18 g (86%). 

A series of diamides of cyclobutane-1,1-dicarboxylic acid gre prepared and reported to have depressant properties. The activity of bis 1,1,l-trichloro-2-propyl)-1,2-cyclobutane-dicarboxylate was shown to be due to the in vivo hydrolysis to the known hypnotic 1,1,l-trichloro-2-pro-panol. Preliminary pharmacological results in mice indi-... 

Draw all possible stereoisomers of cyclobutane-1,2-dicarboxylic acid, and indicate the interrelationships. Which, if any, are optically active Do the same for cyclobutane-1,3-dicarhoxylic acii... 

The two isomeric cyclobutane-1.3-dicarboxylic acids are achiral and are optically inactive. 

H. CaiTell, H.L. Desiraju, G.R. 3-(3, 5Cdinitrophenyl)-4-(2, 5 -dimethoxyphenyl)cyclobutane-1,2-dicarboxylic acid— Engineered topochemical synthesis and molecular and supramolecular properties. Chem. Mater. 1994. 6. 1282-1292. 

Ring and open-chain derivatives of L-erythritol 1,4-dicinnamate have been irradiated yielding products of photochemical asymmetric synthesis, in which intramolecular 2-1-2 cycloaddition occurs to give L-erythritol esters of cyclobutane-1,2-dicarboxylic acid the 2,3-di-O-methyl derivative of l-erythritol gave a high degree of asymmetric induction, whereas the 2,3-0-isopropylidene derivative was much less stereospecific, and gave the opposite cyclobutane enantiomer. ... 

A new method for the preparation of bicyclo[2,l,l]hexenes from cyclobutane-1,3-dicarboxylic acids uses the Ramberg-Backlund reaction of (610) to achieve the final ring closure and introduction of the 2,3-double bond. As a number of substituted cyclobutane-l,3-dicarboxylic acids are readily available, this method should allow the preparation of a variety of substituted bicyclo[2,l,l]hexenes. 

This reaction was initially reported by Franchimont in 1872. It is a condensation of two a-bromocarboxylic acids in absolute alcohol in the presence of sodium cyanide to give 1,2-dicarboxylic acids after hydrolysis and decarboxylation. In the case of a-bromoketones, 1,4-diketones are produced similarly after hydrolysis with phosphoric acid. It was found that the bulky group at the ester end prevents condensation, as in the case of phenyl and naphthyl esters. Although the substituent at j0-position does not prevent such condensation, it reduces the overall yield. In addition, a compound with two ester groups at proper position will form cyclic diacid under such reaction conditions and cyclobutane, " cyclopentane and cyclohexane dicarboxylic acid have been prepared in such a way. In the case of l,4-dibromo-l,4-dibenzoylbutane, a derivative of cyclopentanone is produced after acidic hydrolysis. It should be pointed out that other common solvents—including acetone, ether, and acetonitrile- are not good for this reaction. ... 

Reaction of malonic esters with 1,2-dibromoethane and 1,3-dibromopropane under liquiddiquid two-phase conditions produces the cyclopropane- and cyclobutane- 1,1 -dicarboxyl ic esters, which can be hydrolysed under the basic conditions (6.2.24.C) [e.g. 75, 109] and decarboxylated to give the monocarboxylic acid [e.g. 109]. 

It may be suspected that the genuinely topotactic (as secured by the molecular precision of the AFM [18]) photodimerization of 2-benzyl-5-benzyli-denecyclopentanone [118] might be a good candidate for a quantitative preparative photo dimerization to give the head-to-tail anti-[2+2] dimer. Early quantitative solid-state [2-1-2] photodimerizations (most of the published mechanistic interpretations of which can no longer be accepted) are listed in [110]. These deal with the anti dimerization of acenaphthylene-1,2-dicarboxylic anhydride, the head-to-head syn dimerization of acenaphthylene-1-carboxylic acid, the syn dimerization of 5,6-dichloroacenaphthylene, and the thermally reversible head-to-tail anti dimerization of seven ( )-2,6-di-f-butyl-4-(2-aryl-ethenyl)pyrylium-trifluoromethanesulfonates. All of these reactions proceed fully specific. On the other hand, quantitative photoconversions of a 1 1 mixed crystal of ethyl and propyl a-cyano-4-[2-(4-pyridyl)ethenyl]cinnamates gives mixtures of diesters with one (A>410 nm) or two cyclobutane rings (no cutoff filter). 

A mixture of 0.8 g of [2,2-bis(aminomethyl)-l,3-propanediol-N,N ]dichloroplatinum and 0.78 g of the disilver salt of 1,1-cyclobutane dicarboxylic acid in 50 ml of water was stirred in the dark overnight and then filtered. The filtrate was evaporated to dryness, giving 0.72 g of the desired [2,2-bis(aminomethyl)-l,3-propanediol-N,N ][[l,r-... 

Unlike studies in which acid and base catalysts are distinct molecular species, most attempts to observe bifunctional catalysis when the two catalytic sites are enclosed within the same molecule (whether in the catalyst or in the substrate itself) have failed. First, Lienhard and Anderson (1967) studied acetone iodination catalysed by the monoanions and dianions of a number of dicarboxylic (or polycarboxylic) acids (oxalic acid, 1,1-cyclobutane dicarboxy-lic acid, succinic acid and cis-1,2,3,4-cyclopentanetetracarboxylic acid) for which mechanism (21) can be assumed. It was observed that the catalytic... 

The intramolecular Wurtz-type coupling of dihaloorganic compounds with use of metallic zinc is a classical synthetic route to cyclic compounds. For example, cyclopropane derivatives can be prepared from 1,3-dihalo-propanes (29, 189a, 248, 451), and cyclobutane derivatives from 1,4-dihalobutanes (71). These reactions presumably proceed via the intermediate formation of organozinc compounds. The reaction of diethylzinc with esters of a,a -dibrominated aliphatic dicarboxylic acids leads to the... 

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. ... 

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