Tricyclo undecatrienyl anion

The tricyclo[5.3.1.0]undecatrienyl anion (97) undergoes circumambulatory rearrangement at —78°C to form anion (98) which is happed by D20 at the least hindered anti face to give (99 )-t/1.170 At higher temperature (98) is converted to (102), as indicated in Scheme 7. 

Chemical evidence in support of a circumambulatory cyclopropane ring migration on the periphery of a cyclic polyenide has been reported for the first time. " The rearrangement of tricyclic undecatrienyl anions, derived from tricyclo[5.3.1.0 ]undeca-... 

---