Chrysanthemic acid esters

For the synthesis of permethric acid esters 16 from l,l-dichloro-4-methyl-l,3-pentadiene and of chrysanthemic acid esters from 2,5-dimethyl-2,4-hexadienes, it seems that the yields are less sensitive to the choice of the catalyst 72 77). It is evident, however, that Rh2(OOCCF3)4 is again less efficient than other rhodium acetates. The influence of the alkyl group of the diazoacetate on the yields is only marginal for the chrysanthemic acid esters, but the yield of permethric acid esters 16 varies in a catalyst-dependent non-predictable way when methyl, ethyl, n-butyl or f-butyl diazoacetate are used77). 

Table 4 Chrysanthemic acid ester (allethrin) and modified chrysanthemum acid ester (allethrin...

S,3//,4/C6//)-carane-3,4-diol with (l/ )-tra s-chrysanthemic acid is 0.62, and the Rf. value of the corresponding ( l,S )-/ra .v-chrysanthemic acid ester is 0.65 (toluene ethyl acetate = 3 1). However, the /-menthol ester of (1 /. S )-/ra .v-chrysanthemic acid could not easily be separated by silica gel column chromatography to obtain (1 AfWran.v-chrysanthemic acid /-menthol ester. 

Thus, (1 A S Hra/7.v-chrysanthemic acid was condensed with 1,1 -binaphthol derivative using the TsCb/V-methylimidazole reagent to give the corresponding two sets of diastereomers (26) and (27). From the solution, only the (l/ )-trans-chrysanthemic acid ester (26) crystallized from the diastereomer mixtures. The ester was readily... 

Decomposition of diazoacetate in 2,5-dimethyl-2,4-hexadiene (3 equiv relative to diazoacetate) leads to the pyrethroid chrysanthemic acid esters with moderate enantioselectivity (68% ee trans, 62% ee cis) but poor diastereoselectivity (58 42 trans to cis), Eq. 5. Both the dimer and the pyridyl monomer were found to be equally effective in this reaction. 

When the carbinol substituents (R) were the bulky 5-ler -butyl-2-(n-octyloxy)phenyl group, optimum enantioselectivities were achieved with the catalytic use of the corresponding Cu(II) complex (2) in both enantiomeric forms. Specific applications of the Aratani catalysts have included the synthesis of chrysanthemic acid esters (Eq. 5.6) and a precursor to permethrinic acid, both potent units of pyrethroid insecticides, and for the commercial preparation of ethyl (S)-2,2-dimethylcyclopropanecarboxylate (Eq. 5.2), which is used for constructing cilastatin. Several other uses of these catalysts and their derivatives for cyclopropanation reactions have been reported albeit, in most cases, with only moderate enantioselectivities [26-29],... 

Chrysanthemic acid esters, prepared according to Equation 28, belong to the family of pyrethroids, an important class of insecticides. Both the trans- and the cM-isomers possess insecticidal activity. The other two of the four possible... 

The ds-hydrogenation of cyclopropenes is unexceptional in itself but when preceded by the addition of diazopropane to the yne component of an enyne (Section II.B) it provides a stereospecific synthesis of chrysanthemic acid esters (natural pesticides) in high yield. Reduction of unsymmetrical cyclopropenes with lithium aluminium... 

Davies, M S., Chadwick. P.R.. liolborn, J.M.. Sicw-art, D.C, and Wickham, J.C f 1970). Effectiveness of the (-H-trans-chrysanthemic acid ester of (4)-aNethrulone (hin-allethrin) against lour insect species. Pernio. Set. 1, 225-227,... 

Alkylidene- and ethenylidenecyclopropanes are versatile compounds which have been used, for example, in the synthesis of chrysanthemic acid esters. ... 

They are both chrysanthemic acid esters of (5-benzylfuran-3-yl)methanol (Elliott alcohol, 1) [15]. Patented methods [16] for the industrial preparation of Elliotf s alcohol are demanding or such as to be hardly exploited in industrial-scale plants. For instance, in one of these methods [17] (5-benzyl-3-furyl)methanol is obtained by a sequence of Claisen condensation of benzyl cyanide and a dialkyl succinate, hydrolysis, esterification, protection of the ketone group, formylation, cyclization to 5-benzyl-3-furfuryl ester and reduction to alcohol with lithium aluminium hydride. 

Single isomers of permethric acid, the dihalovinylanalogues of chrysanthemic acid esters, which are sometimes easier to obtain, can also be ozonized to give optionally the optically active caronaldehyde [127, 245] or the epoxides. The epoxides of permethric acid can not be prepared by means of the most reactive peracids [246], the usual epoxidizing agents. 

Hanzawa Y, Ishizawa S, Kobayashi Y. Palladium(O)-catalyzed reactions of trifluoromethylated allylic ester derivatives synthesis of trifluoromethylated chrysanthemic acid ester. Chem. Pharm. Bull. 1988 36 4209-4211. 

---