1,2-DIMETHYLSPIROHEX-1-ENE BY ADDITION OF CYCLOBUTYLIDENE TO 2-BUTYNE
The first addition of a cyclobutylidene (carbenoid) to an alkyne is reported.By C4+C2-coupling the spirohex-1-ene system 8 is constructed.Furthermore, cyclobutylidene adds to methylenecyclopropane, its intramolecular reaction product, to give the novel dispirooctane 11.