Enantioselective total synthesis of (-)-candelalide A, a novel blocker of the voltage-gated potassium channel Kv1.3 for an immunosuppressive agent.

ABSTRACT

A convergent route to (-)-candelalide A involved the union of a trans-decalin portion (AB ring) and a gamma-pyrone moiety through the C16-C3' bond to assemble the whole carbon framework and subsequent formation of the dihydropyran ring (C ring) as the crucial steps. A strategic [2,3]-Wittig rearrangement was employed for establishing the stereogenic center at C9 and an exo-methylene function at C8 present in the decalin portion. [reaction see text]