Ozonolysis activating group

Hydrolysis of cinenn I gives an optically active carboxylic acid (+) chrysanthemic acid Ozonolysis of (+) chrysanthemic acid followed by oxidation gives acetone and an optically active dicarboxyhc acid (—) caronic acid (C7H10O4) What is the struc ture of (—) caronic acid" Are the two carboxyl groups cis or trans to each other What does this information tell you about the structure of (+) chrysanthemic acid" ... 

The preparation of (128) (Scheme 34) highlights the use of the trifluoromethyl group to increase the dipolarophilicity of a ketone. This activating effect of electron withdrawing groups is also taken advantage of in the preparation of 3-carbonyl substituted 1,2,4-trioxolanes (131) via the ozonolysis of a vinyl ethers in the presence of a 1,2-dicarbonyl compound (Scheme 36) <9iJOC659l>. 

Alternative methods for removing 1-propenyl groups under non-acidic conditions have been reported these include reaction with alkaline potassium permanganate solution,204,205 ozonolysis followed by alkaline hydrolysis,204 205 treatment with a mercuric chloride-mercuric oxide reagent,206,207 and treatment with palladium on activated charcoal in a hydroxylic solvent containing a trace of an acid.2070 The last procedure is a combined isomerization-hydrolysis, but the isomerization step may be independently achieved by omission of the acid.2070,2076... 

Nickel(0)-catalyzed [3 + 2] cycloadditions of methylenecyclopropanes with A(-substituted maleimides (56 equation 22) lead almost exclusively to 5-alkylidenehexahydro-l//-cyclopenta[c]pynolo-l,3-diones (57) and (58 equation 23). A similar reaction occurs in the presence of a palladium(O) catalyst, but with lower selectivity. Unsubstituted maleimide and maleic anhydride do not undergo this cycloaddition. Ozonolysis of (57) and (58) into the corresponding ketone derivatives (62-78% yield) followed by reduction of both carbonyl groups gives l//-cyclopenta[c]pynoles, which are of interest with regard to their pharmacological activity (98% yield). ... 

Optically active dialkyl tartrates and (2i ,4/ )-pentane-2,4-diol were used as homochiral protecting groups in a, 6-unsaturated acetals 51 and 52 which were subjected to Simmons-Smith reaction with diethylzinc and diiodomethane to give cyclopropyl derivatives with a de of > 69% (Table 1). The acetal group was readily converted to the aldehyde by acidic hydrolysis or to the acid by ozonolysis. 

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