A catalytic enantioselective hetero Diels-Alder approach to the C20-C32 segment of the phorboxazoles.

[reaction: see text] An efficient synthesis of the C20-C32 segment of the phorboxazoles has been achieved using an enantioselective hetero Diels-Alder reaction catalyzed by Jacobsen's Cr(III) amino indanol Schiff base catalyst.