Synthese von (S)‐Plectaniaxanthin

Synthesis of ( S )‐Plectaniaxanthin The optically active C 10 ‐end group ( S )‐ 5 , prepared from the C 5 ‐aldehyde ( R )‐ 4 ( ex L‐serine ( 2 )), has been used for the synthesis of ( S )‐plectaniaxanthin ( 1 ). The ( R )‐chirality of natural 1 assigned by Rønneberg et al . [6] is confirmed.