Total Synthesis of (±)-8α-Hydroxystreptazolone

The intramolecular Pauson−Khand reaction of 2-oxazolone derivatives with a suitable pentynyl appendage exclusively gave the corresponding 4-hydroxy-6-substituted-9-oxa-1-azatricyclo[6.2.1.0^5,11]undec-5-en-7,10-diones. Based on this newly developed Pauson−Khand reaction of 2-oxazolone-alkyne derivatives, the first total synthesis of (±)-8α-hydroxystreptazolone was accomplished in a highly stereoselective manner.