The lithium enolate of cyclo-octa-2,4,6-trienone and its reactions with electrophiles
Abstract
Lithium di-isopropylamide catalysed rearrangement of 7,8-epoxycyclo-octa-1,3,5-triene at low temperature gives the lithium enolate of cyclo-octa-2,4,6-trienone, which can be alkylated at C-8 with reactive electrophiles such as methyl iodide, allyl bromide, ethyl iodide, benzyl iodide, and benzeneselenenyl bromide. Bromination of the enolate also occurs at C-8, but reagents such as acetyl chloride and ethyl chloroformate yield only the products of O-acylation.