Starting with 1,1,1-trifluoroacetone, 3-(trifluoromethyl)-1-(trimethylsilyloxy)-1,3-butadiene has been prepd. as a mixt. of (Z) and (E) isomers. The diene undergoes [4 + 2] cycloaddn. reactions with a variety of dienophiles affording trifluoromethyl-substi ...
1995