Carotinoidsynthesen über Sulfone; Synthese von Apocarotinoiden und Torularhodinester

The alkylation of conjugated arylsulfonyl ylids, prepared from the corresponding allylic sulfones (2 or 8), and allylic halides bearing terminal carbonylgroups (3 or 4) leads to polyene sulfones which readily undergo spontaneous elimination of the corresponding aryl sulfinates. By this method two apocarotenoids (5 and 6) and torularhodin ethyl ester (9) have been prepared.