Double Cycloisomerization as a Novel and Expeditious Route to Tricyclic Heteroaromatic Compounds:  Short and Highly Diastereoselective Synthesis of (±)-Tetraponerine T6

Abstract

[reaction: see text] Cu-Assisted double cycloisomerization of bis-alkynylpyrimidines afforded the 5-6-5 tricyclic heteroaromatic skeleton. This transformation was used as a key step in the highly diastereoselective total synthesis of (+/-)-tetraponerine T6.