Alkylation of sterically hindered 1,3-diketones under phase-transfer conditions

Article abstract of DOI:10.1007/BF01435389

Sterically hindered 1,3-diketones react selectively with propargyl and allyl bromides under conditions of phase transfer catalysis to give C-alkylated products, whereas reactions with butyl and benzyl chlorides yield mixtures of C- and O-isomers. An increase in the size of the substituents present in the initial 1.3-diketone hampers introduction of the second propargyl group. The propargyl-substittitcd 1,3-diketones undergo cyclization under the alkylation conditions to give substituted furans.