3-CHLOROCYCLOBUTANECARBOXYLIC ACID

Hall and his co-workers43 synthesized several 2-oxabicyclo[2.1.1 ]hexan-3-ones from the corresponding 3-chlorocyclobutanecarboxylic acids. These monomers polymerized readily when heated with a variety of basic or acidic initiators. Some of the results of the polymerization are listed in Table 2. 

CHLOROCYCLOBUTANECAR-BOXYLIC ACID, 51, 73 3-Chlorocyclobutanecarboxylic acid, with mercuric oxide and bromine to give l-bromo-3-chlorocyclo-butane, 51,106... 

Mercuric acetate, reaction with cyclo-octatetraene, 50, 24 Mercuric oxide, use in oxidation of hydrazones, 50, 28 with 3-chlorocyclobutanecarboxylic acid and bromine to give 1-bromo-... 

Chlorocyclobutanecarboxylic acid has been prepared from the rather inaccessible 3-hydroxy-l,l-cyclobutanedicarboxylic acid.4 The related 3-bromocyclobutanecarboxylic acid has also been prepared by a long synthetic scheme of eight steps.5 The present method, based upon the procedure of Nevill, Frank, and Trepka,6 affords the 3-chloro acid in high yield in one step. Thus this method provides a compound which cannot be easily made by other methods. 

The conversion of 3-chlorocyclobutanecarboxylic acid to l-bromo-3-chlorocyclobutane is described in Organic Syntheses.8... 

This enol yields a mixture of cis- and /ra .v-3-chlorocyclobutanecarboxylic acid. The two products are stereoisomers. 

The fore-run contains cyclobutanecarboxylic acid and 3-chlorocyclobutanecarboxylic acid, b.p. 100-130° (15 mm.)... 

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