The regio- and stereo-selective formation of allylic chlorides during the overman rearrangement of trichloroacetimidates derived from certain brominated conduritols

Microwave irradiation of imidate 2 at 165C affords a ∼3:1 mixture of the Overman rearrangement product 3 and the allylic chloride 4 (83% combined yield). Under the same conditions the deoxy-conduritol 6 gives a comparable mixture of compounds 7 and 8. The single-crystal X-ray structure of a derivative of chloride 8 is reported together with a mechanism that accounts for the selective formation of this compound and congener 4.