Reactions of carbonyl compounds with tervalent phosphorus reagents. Part I. Cyclopentadienones

Abstract

Tetracyclone and 2-methyl-3,4,5-triphenylcyclopentadienone react with diphenylphosphine oxide and with dimethyl phosphonate to produce a series of 1 : 1 adducts, in which the phosphorus is attached to the α-carbon of the ketones. In addition, dimethyl phosphonate forms adducts resulting from reaction at the carbonyl group of tetracyclone. Detailed physical evidence for the structures of these adducts is presented, and the factors which control their formation are discussed.