title: Synthesis of labile all-trans-7,8,7',8'-bis-acetylenic carotenoids by bi-directional Horner-Wadsworth-Emmons condensation.
abstract: A new stereoselective synthesis of the C40-bis-acetylenic carotenoids all-trans-(3R,3'R)-alloxanthin and all-trans-3,4,7,8,3',4',7',8'-octadehydro-β,β-carotene, both compounds featuring a stereochemically labile C7-C10 enyne, based on a bi-directional Horner-Wadsworth-Emmons (HWE) reaction of a C15-phosphonate and a central C10-dialdehyde, is reported. The triene unit of the latter fragment was synthesized using the acyclic metathesis/dimerization reaction.
authors.affiliation: Department of Organic Chemistry and Center for Biomedical Research (CINBIO), IBIV, Universidade de Vigo, 36310 Vigo, Spain. qolera@uvigo.es.
authors.forename: Belén
authors.initials: B
authors.lastname: Vaz
authors.forename: Noelia
authors.initials: N
authors.lastname: Fontán
authors.forename: Marta
authors.initials: M
authors.lastname: Castiñeira
authors.forename: Rosana
authors.initials: R
authors.lastname: Álvarez
authors.forename: Ángel R
authors.initials: ÁR
authors.lastname: de Lera
mesh_terms: D000114:Acetylene / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry; D002338:Carotenoids / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D019281:Dimerization; D063065:Organophosphonates / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D011090:Polyenes / Q000737:chemistry; D013237:Stereoisomerism; D024341:Xanthophylls / Q000737:chemistry*; D019207:beta Carotene / Q000737:chemistry*
chemical_list: D000480:Alkynes; D063065:Organophosphonates; D011090:Polyenes; D024341:Xanthophylls; D019207:beta Carotene; D002338:Carotenoids; D010165:Palladium; D003300:Copper; C006462:alloxanthin; D000114:Acetylene