decalin segment 6 required for the totalsynthesis of popolohuanone E (1) was efficiently synthesized starting from the enantiomericallypure (−)-Wieland-Miescher ketone derivative 9; the method features ortho ester Claisen rearrangement of 15 and Ir-catalyzed hydrogenation of 17 (Scheme 2). Furthermore, by employing 6 as the key decalin segment, the first totalsynthesis of natural (+)-arenarol (2) related