Catalytic Asymmetric Total Synthesis of (+)- and (−)-Paeoveitol via a Hetero-Diels–Alder Reaction

The
first catalytic asymmetric total synthesis of (+)- and (−)-paeoveitol
has been accomplished in 42% overall yield via a biomimetic hetero-Diels–Alder
reaction. The chiral phosphoric acid catalyzed hetero-Diels–Alder
reaction showed excellent diastereo- and enantioselectivity (>99:1
dr and 90% ee); two rings and three stereocenters were constructed
in a single step to produce (−)-paeoveitol on a scale of 452
mg. This strategy enabled us to selectively synthesize both paeoveitol
enantiomers from the same substrates by simply changing the enantiomer
of the catalyst.