A novel chromium(0)-promoted three-component alkyne-triene higher-order cyc
loaddition process is presented. The transformation features tethered alkyn
es participating in a tandem [6 pi + 2 pi], [6 pi + 2 pi] cycloaddition eve
nt with cyclic trienes serving as the third reactant. Isomerically homogene
ous products possessing five rings and six stereogenic centers are isolated
from this reaction in good to excellent yield. (C) 2000 Elsevier Science L
td. All rights reserved.