New Colours for Carotenoids â Synthesis of Pyran Polyenes
作者:Christer L. Ãpstad、Hans-Richard Sliwka、Vassilia Partali
DOI:10.1002/ejoc.200901093
日期:2010.1
A new type of carotenoid has been synthesized with a 2H-pyran ring placed in the polyene chain This compound was successively elongated by Wittigreactions. The pyran-carotenoids obtained show a significant increased lambda(max) compared with carotenoids lacking the pyran ring. A further remarkable bathochromic shift was observed upon protonation to pyranium-carotenoids. The pyranium ring is the distinctive