Potentialimmunosuppressiveagents: Candelalides A, B and C (see figure), novel blockers of the voltage‐gated potassium channel Kv1.3, have been efficiently synthesized for the first time in a convergent and unified manner starting from (+)‐5‐methyl‐Wieland–Miescher ketone. The method explored has potential for preparing various types of candelalide analogues for the structure–activity relationship
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