Practical Synthesis of ε-Carotene

Abstract

A novel route for the total synthesis of ε-carotene is described. The synthesis is based on a condensation between α-cyclocitral and diethyl [(2E)-3-methoxy-2-methylprop-2-en-1-yl]phosphonate to give a C 14 enol ether, hydrolysis of the C 14 -enol ether to a give a C 14 aldehyde, and a modified Wittig-Horner reaction of the C 15 phosphonate from the C 14 aldehyde and a C 10 triene dialdehyde to give ε-carotene. The synthetic steps are easily performed and are practical for largescale production.

The sources, properties, extraction, biosynthesis, pharmacology, and application of lycopene

“…The synthesis process of lycopene was characterized by Wittig Horner condensation reaction reaction 23–25 as follows: (1) using geraniol (A) as the raw material, citral (B) was obtained through oxidation; (2) (B) reacted with C 4 -phosphonate to obtain C 14 -enol ether (C); (3) (C) was hydrolyzed to obtain C 14 -aldehyde (D); (4) the key intermediate C 15 -phosphonate (E) was obtained by the reaction of (D) with gemini phosphonate; and (5) lycopene (F) was obtained by the condensation of (E) with decarbondialdehyde. The synthetic route of lycopene is shown in Fig.…”