Asymmetric synthesis of gamma-hydroxy alpha,beta-unsaturated aldehydes via enantioselective direct addition of propargyl acetate to aldehydes. 
We report the first example of enantioselective and diastereoselective aldehyde additions of propargyl acetate to aldehydes using the methodology recently reported from our laboratories.  Subsequent O-silyl protection, Pd-catalyzed isomerization, AcOH addition, and hydrolysis result in optically active gamma-hydroxy alpha,beta-unsaturated aldehydes as powerful building blocks.  Reaction: see text.