Synthesis of the C17–C30 Bis-THF Fragment of Iriomoteolide-13a via Intramolecular syn-Oxypalladation of 26-Ene-17,21,23,28-tetraol

Abstract

The fully substituted C17–C30 bis-tetrahydrofuran fragment of the proposed structure of iriomoteolide-13a has been assembled via asymmetric dihydroxylation–SN2 cyclization of 19-mesyloxy-21-ene-26-yne and PdCl2-catalyzed syn-oxypalladation of 26-ene-17,21,23,28-tetraol as the key steps. The syn-oxypalladation process gave an 89:11 diastereoselectivity and tolerated the free poly-hydroxy groups in the highly functionalized substrate.