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Synthese und Chiralität von (5 R , 6 R )‐5,6‐Dihydro‐β, ψ‐carotin‐5,6‐diol, (5 R , 6 R , 6′ R )‐5,6‐Dihydro‐β, ε‐carotin‐5,6‐diol, (5 S , 6 R )‐5,6‐Epoxy‐5,6‐dihydro‐β, ψ‐carotin und (5 S , 6 R , 6′ R )‐5,6‐Epoxy‐5,6‐dihydro‐β,ε‐carotin
Author(s) -
Eschenmoser Walter,
Uebelhart Peter,
Eugster Conrad Hans
Publication year - 1979
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19790620804
Subject(s) - chemistry , optically active , stereochemistry , diol , reagent , wittig reaction , carotene , chirality (physics) , absolute configuration , organic chemistry , chiral symmetry , quantum mechanics , physics , nambu–jona lasinio model , quark
Synthesis and Chirality of (5 R , 6 R )‐5,6‐Dihydro‐β, ψ‐carotene‐5,6‐diol, (5 R , 6 R , 6′ R )‐5,6‐Dihydro‐β, ε‐carotene‐5,6‐diol, (5 S , 6 R )‐5,6‐Epoxy‐5,6‐dihydro‐β,ψ‐carotene and (5 S , 6 R , 6′ R )‐5,6‐Epoxy‐5,6‐dihydro‐β,ε‐carotene Wittig ‐condensation of optically active azafrinal ( 1 ) with the phosphoranes 3 and 6 derived from all‐( E )‐ψ‐ionol ( 2 ) and (+)‐( R )‐α‐ionol ( 5 ) leads to the crystalline and optically active carotenoid diols 4 and 7 , respectively. The latter behave much more like carotene hydrocarbons despite the presence of two hydroxylfunctions. Conversion to the optically active epoxides 8 and 9 , respectively, is smoothly achieved by reaction with the sulfurane reagent of Martin [3]. These syntheses establish the absolute configurations of the title compounds since that of azafrin is known [2].