Novel One-Pot Cycloisomerization-Knoevenagel Condensation Sequences with Yne Allyl Alcohols

The sequential Pd-catalyzed cycloisomerization-Knoevenagel condensation of alkyne allyl alcohols 1 and CH-acidic compounds, such as acetylacetone (2a), dimethyl malonate (2b) or malononitrile (2c), furnishes the 2,6-dienes 3 in moderate to good yield. Upon reacting 1,3-cyclohexadione (4a) or dimedone (4b) under the same reaction conditions pseudo-threecomponent products 5 are formed as a consequence of a consecutive cycloisomerization-condensation-addition sequence in 57-88% yield.