Total synthesis of C31-methyl ketone apocarotenoids. Part 4. First total synthesis of (3S,5R,6R)-paracentrone

Optically active (all-E)-(3S,5R,6R)-paracentrone has been prepared by total synthesis for the first time, in 3% overall yield over 13 linear steps from the readily available (4R,6R)-actinol, (2E)-3-methylpent-2-en-4-yn-1-ol, (all-E)-2,7-dimethylocta-2,4,6-triene-1,8-dial and 1,1-dimethoxypropan-2-one. All spectral data for synthetic (all-E)-(3S,5R,6R)-paracentrone are in accordance with data reported for the natural compound.