Rearrangements of 4-Alkynylcyclobutenones. Annelated Spiroepoxycyclohexadienones and Quinones from 4-(1,5-Dialkynyl)-4-methoxy(or hydroxy)cyclobutenones

Article abstract of DOI:10.1021/jo00040a008

4-(1,5-Dialkynyl)-4-methoxycyclobutenones 1 were shown to undergo a unique rearrangement to annelated spiroepoxides 6 upon thermolysis in toluene.The 4-hydroxy analogs also ring expand giving either quinones 13 or 14 as a function of the reaction solution