Chrysanthemum acid synthesis

Versatile procedures have been developped particularly for the latter sequence - one illustrative example, leading to a simple synthesis of cis-chrysanthemum acid, is shown in Scheme 67. ... 

Chondrodendron polyanthum, 371 Chondrodendron tomentosum, 363, 371, 373, 377, 391 alkaloids, 376 Chondrodine, 363, 364 Chondrofoline, 364, 365 Chrycentrine, 172, 313 Chiysanthemine, 773 Chrysanthemum cineraricefoHum, 773 Chuchuara, 781 Chuehuhuasha, 781 Cicuta virosa, 13 Cinchamidine, 419, 429 Cinchene, 439 Cinchenine, 438, 439, 440 apoCinchenine, 440, 441 Cincholoipon, 438 Cincholoiponic acid, 438, 443 Cinchomeronic acid, 183 Cinchona alkaloid structure, synthesis, 457 Cinchona alkaloids, bactericidal action of some derivatives, 478 centres of asymmetry, 445 constitution, 435 formulae and characters of transformation products, 449, 451 general formula, 443 hydroxydihydro-bases, 448, 452-4 melting-points and specific rotations, 446... 

Inouye Y, Takeshita Y, Ohno M (1955) Studies on synthetic pyrethroids V. Synthesis of geometrical isomers of chrysanthemum dicarboxylic acid. Bull Agric Chem Soc Jpn 19 193-199... 

Synthesis of (Z)-(lR)-tranH-Norchrysanthemic Acid by Pyrolytic Reaction of Chrysanthemum Dicaroboxylic Acid Monomethyl Ester with a New Catalyst... 

Numerous studies of the photoreactions of dihydrofurans have been described. On irradiation 2,3-dihydrofurans are known to undergo conversion to acylcyclopropanes by a pathway involving initial carbon-oxygen bond homolysis. The /i-enamino ester (162), for example, affords the cyclopropane (163) on triplet-sensitized irradiation.138 Similar transformations have been observed in 2,2,4-triacyl-2,3-dihydrofurans,139 and a synthesis of a cis-trans mixture of chrysanthemum carboxylic acid has been accomplished in this way.140 The conversion of the 2-thiazolines(164) to the iV-alkenylthio-amides (165) presumably involves an analogous carbon-sulfur bond homolysis, followed by a 1,2-hydrogen shift in the resulting biradical (166).141... 

In the past carbohydrates have often proved useful as enantiomerically well defined starting materials. Now Fraser-Reid and Fitzsimmons have utilized (24) as starting material in a synthesis of both of the enantiomers of chrysanthemic acid in an optically pure state. ° The chrysanthemum dicarboxylic acid analogue (26)... 

---