γ-Carotene (m. p. 153°) has been synthesized by a WITTIG reaction of either dehydro-β-apo-l2′-carotenal(C25) (V) with pseudo-ionylideneethyl-triphenylphosphonium chloride (IV) (C25 + C15 = C40) or of β-apo-8′-carotenal(C30) (VII) with geranyltriphenylphosphonium bromide (VIII) (C30 + C10 = C40).
γ-胡萝卜素(mp 153°)通过脱氢-β-apo-l2'-胡萝卜素(C 25)(V)与伪亚亚乙基乙基三苯基氯化chloride(IV)的WITTIG反应合成(C 25 + C 15= C 40)或β-apo-8′-胡萝卜素(C 30)(VII)与香叶基三苯基溴化phosph(VIII)(C 30 + C 10= C 40)。
1,2,5,6-Tetrahydro-2,6-cyclo-gamma-carotene-1,5-diol, an oxidation product of the pro-vitamin A food carotenoid.-carotene, was synthesized by a C-15 + C-10 + C-15 double Wittig coupling strategy. The total synthesis involved a key C15-dihydroxyaldehyde synthon derived from (E/Z)-citral, a protected C-10-Wittig salt, and (beta-ionylideneethyl) triphenylphosphonium chloride (C-15-Wittig salt). This synthetic route provides novel access to an oxidation product of gamma-carotene that could be potentially formed in humans or biological systems as a consequence of metabolic oxidation.