Syntheses of Carotenes with yr-End Groups and (Z)-Configuration at1. Einleitung. -Nach unserem Vorschlag [Z] [3] lasst sich die Bildung der 8-, E -und

Reaction of 1-benzyl-3,5-dibromo-1 H -[1,2,4]triazole (3) with cesium fluoride yielded selectively 1-benzyl-3-bromo-5-fluoro-1 H -[1,2,4]triazole (4) . Debenzylation and realkylation afforded 1-alkyl-5-bromo-3-fluoro-1 H -[1,2,4]triazoles 7 , which reacted with a wide variety of nucleophiles to give 5-substituted 1-alkyl-3-fluoro-1 H -[1,2,4]triazoles.

Aus einem Gemisch der in der vorangegangenen Arbeit synthetisierten Carotine werden die Titelverbindungen (III), (VIIIa), (VIIId) und (XIb) von den Vergleichssubstanzen (VIIIb), (VIIIc), (VIIIc), (XIa) und (XIII) abgetrennt (H PLC‐Daten).

HPLC of Carotenes with ψ‐End Groups and (Z)‐Configuration at Terminal Conjugated Double Bonds; Isolation of (5Z)‐Lycopene from Tomatoes Five carotenes bearing (5Z)‐ψ‐end groups were synthesized and carefully characterized: (5Z)‐lycopene (6), (5Z5′Z)‐lycopene (7), (5′Z)‐neurosporene (8), (5′Z)‐β,ψ‐carotene (12), and (5′Z)‐ε,ψ‐carotene (14). Lycopene 6 was isolated from tomatoes and its structure proven by 1H‐NMR spectroscopy.