1- Methyl-2-cyclopropanecarboxylic acid

Cyfluthrin-met/ty/-fi(6 (provided in acetonitrile solution by Bayer Corp.) Cyfluthrin stable-isotope internal standard (IS), Cyclopropanecarboxylic acid, 3-(2,2-dichloroethenyl)-2,2-dimethyl-, cyano(4-fluoro-3-Phenoxyphenyl)methyl ester-met/tyWe, molecular formula C22H12D6CI2FNO3, molar mass 440.3, ion observed at 213.0 (GC/MS)... 

Methyl 2,2-dimethyl-3-(trimethyl iloxy)-1-cyclopropanecarboxylate Cyclopropanecarboxylic acid, 2,2-dimethyl-3-[(trimethylsilyl)oxy]-, methyl ester (10) (77903-45-8)... 

Cyclopentanes, synthesis, 66, 10 CYCLOPEKTANONE SYNTHESIS, 66, 87, 92, 93 Cyclopentanone, 2-carbomethoxy-3-vinyl, 66, 56 Cyclopentanone, 2-ethenyl-2-methyl (88729-76-4), 66, 94 2-CYCLOPENTEN-l-ONE, 3-METHYL-2-PENTYL-, 65, 26 Cyclopropane, l-trimethy1s1lyloxy-1-ethoxy-, 56, 44 Cyclopropanecarboxylic acid chloride, 66, 176... 

Recently, the cyclopropanation of (Z)-4-benzyIidene-2-phenyl-5(4//)-oxazolone 621 with phenyldiazomethane was reported to give the spirocyclopropane, rac- 21 in very high yield. Subsequent ring opening and hydrolysis of rac- 21 generated frani-l-amino-2,3-diphenyl-l-cyclopropanecarboxylic acid, rac-828 (cadiPhe) (Scheme 7.256). This new, constrained phenylalanine analogue induces a y-tum in the sohd state when incorporated into model dipeptides. The enantiomers of the Al-Boc (Boc = tert-butyloxycarbonyl) methyl ester of 828 have been resolved by HPLC. 

In the examples given the preparative value depends upon the ready availability of the required methyl ketone thus pinacolone (Expt 5.98), cyclopropyl methyl ketone (Expt 7.1) and mesityl oxide (Expt 5.213) are converted into 2,2-dimeth-ylpropanoic acid, cyclopropanecarboxylic acid and 3,3-dimethylacrylic acid respectively (Expts 5.124 and 5.125). 

Alkylation of cyclopropanecarboxylic acid esters,6 Deprotonation of methyl silyloxycyclopropanecarboxylates (1), prepared as shown, is possible with LDA in THF at — 78°. The resulting anions react with primary alkyl iodides and benzylic or allylic bromides to give 2 in high yield. These products are cleaved by F to methyl 4-ketocarboxylates 3. 

CYCLOPROPANECARBOXYLIC ACID, 3-(2,2-DIBROMOVINYL)-2,2-DIMETHYl-, CYANOl3-PHENOXYPHENYL) METHYL ESTER, cii-tO-... 

Permethrin (cyclopropanecarboxylic acid, 3-(2,2-dichloroethenyl)2,2-dimethyl-(3-phenoxyphenyl)methyl ester)... 

Similarly, 144 has been obtained from the reaction of 1-trimethylsilylcyclopropyl methyl selenide with n-BuLi The a-bromosilane 147 underwent lithiation with n-BuLi in THF at —78 °C to provide 144 with superior efficiency to any other method, Eq. (46))81). 147 was prepared in large quantities by the Hunsdiecker degradation of the 1-trimethylsilylcyclopropanecarboxylic acid 146, obtained by successively reacting the commercially available cyclopropanecarboxylic acid with -BuLi (2 equivalents) and ClSiMe3 82). Uneventfully, 144 added to carbonyl compounds, except for cyclopentanone where enolate anion formation competed the 1-trimethylsilylcyclo-propylcarbinols 148 underwent acid-induced dehydration to the expected 1-trimethyl-silylvinylcyclopropanes 149 79-81) while base induced elimination (KH, diglyme, 90 °C) led to cyclopropylidenecycloalkanes 150 77), Eq. (47). 

Since alkoxysubstituted methyl cyclopropanecarboxylates like 66 undergo ring opening upon acid treatment to provide the y-oxoester 67, the cyclopropanation/ring cleavage sequence establishes an overall nucleophilic acylation of a,(5-unsaturated esters 40). 

The strain energy of the cyclopropane ring is determined from thermochemical measurements on two closely related compounds the /r-butyl ester of cyclopropanecarboxylic acid and the methyl ester of cyclohexanecarboxylic acid. Both compounds can be synthesized from the appropriate acid chlorides, and their heats of combustion measured with a bomb calorimeter. 

SYN CYCLOPROPANECARBOXYLIC ACID, 3-(2,2-DICHLOROETHENYL)-2,2-DIMETHYL-, CYANO(3-PHENOXYPHENYL) METHYL ESTER, MIXED WITH ACETIC ACID ANHYDRIDE, 5-((2-(2-BUTOXYETHOXY) ETHOXY) METHYL)-6-PROPYL-l,3-BENZODIOXOLE, DIMETHYLBENZENE AND 1-METHYL 2-PYRROLIDIN ONE... 

SYNS CYCLOPROPANECARBOXYLIC ACID, 3-(2-CHLORO-3,3,3-TRIFLUORO-l-PROPENYL)-2,2-DIMETHYL-,CYANO(3-PHENOXYPHENYL)METHYL ESTER, (l-a(S ),3-a(Z))-(+-)- CYHALOTHRIN K ICON KARATE LAMBDA-CYHALOTHRIN TECHNICAL PP 321 LAMBDA-CYHALOTHRIN... 

The nature of the lithium surface is important. Varying the particle size of the lithium dispersion from 25 pm with a surface area of 2782 cm to 150 pm with a surface area of 464 cm reduced the optical purity of the resulting acid by nearly 50%. It was also demonstrated that the amount of sodium impurity in the lithium dispersion had a significant effect not only on the stereochemical results of the metallation reaction but also on the reactivity of the metal surface itself. For example, reaction of chiral l-iodo-2,2-diphenylcyclopropane with 25 pm lithium dispersions containing 0.002 %, 0.02 % and 1 % sodium yielded after carbonation l-methyl-2-cyclopropanecarboxylic acid (99) with optical purities of 13 %, 16% and 36%, respectively. The increase in optical purity with increase in sodium content may be a consequence of lowering the ionization potential of the metallic surface . ... 

Methyl cyclopropanecarboxylate Cyclopropanecarboxylic acid, methyl ester (8,9) (2868-37-3)... 

Substitution of a halomercury group attached to a cyclopropane has also been carried out via a cyclopropyl anion. When cii-2-(diisopropylaminocarbonyl)-2-methylcyclopropyltnercury chloride (2) was treated sequentially with an excess of methyllithium or methylmagnesium bromide and then with carbon dioxide, acidic aqueous workup gave, in very good yield, cis-2-(diisopropylaminocarbonyl)-2-methylcyclopropanecarboxylic acid (3a, 74% from 2), which was esterified with diazomethane to give methyl cw-2-(diisopropylaminocarbonyl)-2-methyl-cyclopropanecarboxylate (3b, 90% from 2 when 3a was not isolated). ... 

This profound transformation occurs on treatment of aryl-substituted cyclopropanes with powerful oxidizing agents, such as ozone and ruthenium(Vlll) oxide to give the corresponding cyclopropanecarboxylic acids. The results obtained using ozone appear to be sensitive to the reaction conditions, therefore, ruthenium(VIII) oxide has become the reagent of choice for such transformations. An exception is the formation of the monomethyl ester of tran5-l,2-cyclopropanedicarboxylic acid in quantitative yield by ozone treatment of methyl t/ nA-2-phenylcyclopropanecarboxylate. ... 

Cyclopropanecarboxylic acid, 56, 70 Cyclopropanes, em-dihalo, 56, 32 Cyclopropanone ketals, 58, 40 Cyclopropenes, 58, 40 CYCLOPROPENONE, 57, 41 CYCLOUNDECANONE, 56, 107 Cycloundecanone, 2-hydroxy-, 56, 110 Cycloundecene, 1-carboxy-, 56, 111 Cycloundecene, 1-methoxy-, 56, 111 1-Cycloundecene-l-carboxylic acid, methyl ester, 56, 108... 

The (S)-serine derived methyl ( R)-2- erJ-butyl-2,3-dihydrooxazole-3-carboxylate reacts with ethyl diazoacetate under bis(2,4-pentanedionato)copper catalysis to afford the expected bi-cyclic product in good yield54, but in this case the inducing power exhibited by the bulky 2-tm-butyl group is rather weak (diastereofacial selectivity 70 30). However, the major diastereomer can be easily separated by chromatography and selective saponification to give the enantiomerically pure cyclopropanecarboxylic acid. 

Blnresmethrin. (IR-trans)-2,2-Dimer hyl-3-<2-methyi-1 -propenyl)cyclopropanecarboxylic acid [5-<phenyl-methyl)-3-furanyt methyl ester,- trans-(+)-2.2-dimetlryl-3-(2-methylpropenyl)cyclopropanecarboxyiic acid (S.benzyl-3-... 

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