Electrocyclic Ring-Opening of 6,6-Dichlorobicyclo[3.1.0]-hexanes and Trapping of the Resulting π-Allyl Cations by C-1 Tethered Hydroxyamine Derivatives: Formation of 2-Oxa-1-azaspiro[4.5]decan-3-ones

Abstract

The C-1 substituted 6,6-dichlorobicyclo[3.1.0]hexanes 1a–c have been prepared and shown to undergo electrocyclic ring-opening to give the corresponding π-allyl cations 2 that cyclise to afford the spirocyclic products 3b–d, each of which has been subjected to single-crystal X-ray analysis.