Carone aldehyde

Russian workers have reported the preparation of an unusual 11,12,14,15-tetradehydro-(5S, 6R)-dimethylmethanoleukotriene A4 analog 68. The compound was prepared in seven steps from the chiral keto aldehyde synthon, caronic aldehyde 69 (Scheme 5.25). 

Caron aldehyde ester was of great help particularly for the casual preparation of many chrysanthemic acid analogues for insecticidal research. Instead of triphenyl phosphine the trisdimethylamino phosphine may be apphed preferentially [247]. The production of caronaldehyde 755 by the route outUned above is still essential for the production of deltamethrin. Alternatively to the Wittig reaction, the dichlorome-thylene moiety may be introduced by reaction of carbenoids or carbanions from haloforms with the hemiketal 158 of free cis-caronaldehyde, (reaction scheme 100) [248, 249] and subsequently completed by dehalogenation processes. 

The synthetic principle of the latter 1,3-cycloelimination was applied in a synthesis of optically active caron aldehyde precursors, involving the transfer of chirahty from an unsaturated acyl proline 167 (261) (Reaction scheme 106) to an iodo lactone 168 which is processed further to yield two diastereomerically related add derivatives 169, 170. 

Fujitani [6] separated the insecticidally active syrupy ester from pyrethrum flowers in 1909 and named the ester pyrethron. Yamamoto [7, 8] subjected the hydrolysis product of this pyrethron to ozone oxidation, and isolated Iram-caronic acid and aldehyde (1 and 2, respectively, Fig. 3). Although Yamamoto did not determine the structure of this acid, he presumed it to be pyrethron acid (Fig. 3). Eventually, the presence of a cyclopropane ring in the molecule of natural pyrethrins became clear for the first time in 1923. 

Mathivet, T. Meliet. C. Castanet. Y. Mortreux. A. Caron, L. Tilloy. S. Monflier, E. Rhodium catalyzed hydroformylation of water insoluble olefins in the presence of chemically modified P-cyclodextrins Evidence for ligand-cyclodextrin interactions and effect of various parameters on the activity and the aldehydes selectivity. J. Mol. Catal., A Chem. 2001, 176. 105-116. 

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