Total Synthesis of epi-Trichosetin.

The natural 3-decalinoyltetramic acid epi-trichosetin was synthesized in ten steps starting from ( R)-(+)-citronellal using an intramolecular Diels-Alder reaction and a Lacey-Dieckmann cyclization as the key steps. The use of a 2-nitrobenzyl protecting group resulted in an efficient synthetic endgame. The natural product was obtained in 4.1% overall yield.