Pericyclic Reactions of Free and Complexed Cyclopentyne.
The selectivity between [2 + 2] and [2 + 4] cycloadditions of cyclopentyne with spiro[2.4]nona-2,4-diene depends on the mode of generating the cycloalkyne. Using diazomethylenecyclobutane and (bromocyclobutylidenemethyl)trimethylsilane as precursors affords cyclopentyne in an unencumbered form, whereas using dibromomethylenecyclobutane and 1,2-dibromocyclopentene yields a cyclopentyne-lithium bromide complex.
Gilbert
John C.
JC
Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712.
Hou
Duen-Ren
DR
Grimme
Julian W.
JW