2- Methylcyclopropane carboxylic acid

A higher yield under similar reaction conditions was observed when a phosphoryl-substituted carbanion reacted with nonsterically hindered methyloxirane to give 2-methylcyclopropane-carboxylic acid (2). ... 

Fig. 6. Crystal structure of 2,2-diphenyl-l-methylcyclopropane carboxylic acid (VII), lowing the hydrogen-bonding chain running along the direction of the 6-axis. Access of ammonia to the carboxyl groups in the directions of the a- and c-axes is effectively prevented by the bulky hydrocarbon moieties.

Hunsdiecker reaction of the silver salts of both cis-(56) and trans-2-methylcyclopropanecarboxylic acid (57) yielded the same mixture of cis- (58) and trans-1-bromo-2-methylcyclopropane (59), thus demonstrating that the 2-methylcyclopropyl radical was incapable of maintaining its configuration . Brominative decarboxylation of the silver salts of exo- (60) and em/o-norcarane-7-carboxylic acid (61) produced the same mixture (16 84) of exo- (62) and entio-7-bromonorcarane (63)". Similarly, cis- and trans-silver 1,2-cyclopropanedicarboxylate gave rise to the same isomer ratio (24 76) of cis- and fraws-1,2-dibromocyclopropane. Consistent with these results is the report that the Hunsdiecker reaction with the silver salt of trans-2,2,3-d3-cyclopropanecarboxylic acid (64) gives an equimolar mixture of cis- (65) and rrans-2,2,3-d3-cyclopropane (66) . 

Rodewald and Lewis oxidized trans- and cis-2-methylcyclopropane-l-carboxylic acids (62 and 63) both on Pt and C anodes and from each they obtained the mixture of the isomers 64 and 65, in about 4 1 ratio. Based on these results they concluded that a... 

In these substances,as in tne 1,2,3 derivatives, it ie interesting to compare two cyclopropanes differing only by tne substitution of a carboxyl group by methyl two such compounds are tne 1,1,2,3 tetra acid and methylcyclopropane 2,2,3 triacid ... 

These two compounds,the 1,1 acid and the methylcyclopropane 2,2 acid are interesting to contrast us they differ only in that a carboxyl group in one is replaced by a methyl group in the other. On heating to 18 - - 19O the first loses carbon dioxide,but no ring cleavage products result the second at a temperature of 190 also loses carbon dioxide but about 75 per cent of the product is valerolactone, 0H -0H - fUa... 

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