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Key Word Index - Prunus persica; Rosaceae; C25-epoxy-apo-carotenoids; apo-carotenols; persicaxanthin; persicachrome.Persicaxanthin, obtained from the fruits of peach, has been isolated in crystalline form.By spectroscopic (MS, 1H NMR and CD) methods, its constitution and absolute stereochemistry have been determined as (3S,5R,6S)-5,6-epoxy-3-hydroxy-5,6-dihydro-12'-apo-β-carotene-3,12'-diol.The structural conclusions have received full support by comparison with semi-synthetic persicaxanthin obtained from natural violaxanthin.

Starting from (1'S,2'R,4'S,2E,4E)-5-(1',2'-epoxy-4'-hydroxy-2',6',6'-trimethylcyclohexyl)-3-methyl-2,4-pentadienal (3), a recently described synthon , a full range of C20-, C25-, C27-, and C30-polyenic acids, alcohols, and aldehydes and their (8R)- and (8S)-diastereomeric furanoid rearrangement products was prepared.The synthetic C25-alcohols proved to be identical with persicaxanthin (= 12'-apoviolaxanthin-12'-ol) and persicachromes (= 12'-apoauroxanthin-12'-ols) and the C27-alcohols analogously with sinensiaxanthin and sinensiachromes.A correlation between the sign of the Cotton effects in the CD spectra of 5,6- and 5,8-epoxides and their configuration at C(6) and C(8), respectively, was established.