Gold(I)‐Catalysed Cycloisomerisation of 1,6‐Cyclopropene‐enes

Abstract

The gold(I)‐catalysed cycloisomerisation of appropriately substituted 1,6‐cyclopropene‐enes proceeds through regioselective electrophilic ring opening of the three‐membered ring to generate an alkenyl gold carbenoid that achieves the intramolecular cyclopropanation of the remote olefin. This strategy allows straightforward, highly efficient and diastereoselective access to a variety of substituted 3‐oxa‐ and 3‐azabicyclo[4.1.0]heptanes, as well as to bicyclo[4.1.0]heptan‐3‐ol derivatives. Since the isopropylidene group in the resulting cycloisomerisation products can be subjected to ozonolysis, 3,3‐dimethylcyclopropenes behave as interesting surrogates for α‐diazoketones.