摘要:
The first 3-->6 type ring-closing dienediyne synthesis by means of a McMurry reaction was realized by converting the ketoaldehyde 20 into the 6-/10-membered bicyclic dienediyne 22. Diastereoselective pinacol couplings 20-->23 and 21-->24 giving 6-/10-membered bicyclic enediynediols were possible, too. (C) 1997 Elsevier Science Ltd.