Stereoselective total synthesis of ent-EI-1941-2 and Epi-ent-EI-1941-2.

The first asymmetric total syntheses of ent-EI-1941-2 and epi-ent-EI-1941-2 have been accomplished, starting from a chiral epoxy iodoquinone 6, a key intermediate in our total syntheses of epoxyquinols A and B. A key step in the preparation of ent-EI-1941-2 is an intramolecular carboxypalladation via a 6-endo cyclization mode, followed by beta-hydride elimination, while carboxymercuration is a key step in the synthesis of epi-ent-EI-1941-2. [reaction: see text]