Highly stereoselective synthesis of (Z)- or (E)-double bonds with conformational control in [3,3]sigmatropic ring expansion of 8-membered thionocarbonates
The highly stereoselective synthesis of (Z)- or (E)-double bonds in 1O-membered thiolcarbonates was successfully conducted by controling the chairlike-boatlike transition states in the [3,3]sigmatropic rearrangement of 8-membered thionocarbonates.