2- -cyclo propanecarboxylic acid

Allethrin, DL-2-allyl-3-methyl cyclopenten-l-one ester of dl-cis-trans-2, 2-dimethyl-3 (-2-methylpropenyl) cyclo-propanecarboxylic acid... 

A carboxy group is a rather weak electron-withdrawing substitutent and its electronic effect on the adjacent double bond is negligible. The fact that the straightforward synthesis of cyclo-propanecarboxylic acids via the addition of dichlorocarbene to alk-2-enoic acids has met with a little success is, therefore, due to the acidic properties of this substituent. 

Two iodocyclopropanes have been prepared by decarboxylation of the corresponding cyclo-propanecarboxylic acids with lead(IV) acetate in the presence of iodine and iodosobenzene diacetate in the presence of iodine. ... 

Other electron-withdrawing substituents which have been used to stabilize cyclopropyl anions are the acyl, ° carboxy, ° nitro, and isocyanide groups. With one exception, the first three were unsuccessful, partly because other reactions took place. Thus, cyclopropanecarboxylic acid undergoes dimerization to l-(cyclopropylcarbonyl)cyclo-propanecarboxylic acid, and this reaction predominates above room temperature. When ni-trocyelopropane was treated with base spontaneous dimerization oceurred, yielding mixtures of 1-nitro-l-nitrosobicyclopropyland l,l -dinitrobicyclopropyl. The yields of the two products were dependent on the workup procedure employed. 

Cyclopropyl methyl ketones have also been obtained by reaction of anhydrides of cyclo-propanecarboxylic acids with methyllithium. ... 

Another interesting example of the rearrangement has recently been reported by Samet and coworkers [26], who describe a reaction of levoglucosenone with sulfur ylides to form unusual cyclopropane derivatives. These annulated cyclopropanes were smoothly converted by 30% aqueous hydrogen peroxide in acetic acid to cyclo-propanecarboxylic acids. The final acid hydrolysis (MeOH/HCl) converted them into synthetically valuable cyclopropanated lactones. This case of the Baeyer-Villiger rearrangement reaction is depicted in Scheme 9.9. 

The procednre for this synthesis is essentially the same as that for the n-butyl cyclo-propanecarboxylate described above. In the present case 3.8 g (0.12 mol) of methanol is used. [If commercially prepared acid chloride is used, add 8.80 g (0.06 mol).] Since... 

The trimethylsiloxy group can also act as a donor function and gives rise to the formation of similar cleavage products with a methoxy substituent. When alkyl 2-(trimethylsiloxy)cyclo-propanecarboxylates 21 were treated with acid, products arising from an aldehyde intermediate were obtained. ... 

---