The nature of cyclopentyne from different precursors

Article abstract of DOI:10.1016/S0040-4020(97)00334-7

The ratio of [2+2] and [2+4] cycloaddition products from reaction of spiro[4.2]hepta-1,3-diene with cyclopentyne depends on the source of the cyclopentyne. A mechanistic rationale for the phenomenon is presented.