SYNTHESIS, CHEMICAL TRAPPING AND DIMERIZATION OF TRICYCLO[3.3.0.0(3,7)]OCT-1(5)-ENE, THE CONSUMMATE MEMBER OF A SERIES OF PYRAMIDALIZED ALKENES

The synthesis of tricyclo[3.3.0.0(3,7)]oct-1(5)-ene, 5, the consummate member of a series of pyramidalized alkenes, has been carried out by deiodination of 4 in different ways. Reaction of 4 with sodium in boil ing dioxane gave in good yield diene 8, whose formation can be easily explained through the intermediacy of 5 and its cyclobutane dimer 6. R eaction of 4 with t-butyllithium in THF at -78 degrees C in the presen ce of 1,3-diphenylisobenzofurane gave 10, a Diels-Alder adduct derived from 5. Copyright (C) 1996 Elsevier Science Ltd