Carotinoide mit 7‐Oxabicyclo[2.2.1]heptyl‐Endgruppen. Teil II. Synthese von (2S,5R,6S,2′S,5′R,6′S)‐2,5:2′5′‐Diepoxy‐5,6,5′,6′‐tetrahydro‐β,β‐carotin

Abstract

Carotenoids mit 7‐Oxabicyclo[2.2.1]heptyl‐End Groups. Synthesis of (2S,5R,6S,2′S,5′R,6′S)‐2,5:2′5′‐Diepoxy‐5,6,5′,6′‐tetrahydro‐β,β‐carotene Mukayama's ester 6 (methyl (1S,2R,5S)‐2,5‐epoxy‐2,6,6‐trimethylcyclohexane‐1‐carboxylate) was transformed in a few conventional steps into the title compound 14. Its CD curve was found to be significantly different from that of the analogous 3,6‐epoxide, a fact we tentatively lake as an indication of a (weak) electronic interaction between the ring O‐atom and the π‐orbitals of the polyene chain.