Novel Knöevenagel-type reaction via titanium enolate derived from Ti(O-i-Pr)4 and diketene

Abstract Knoevenagel-type reaction between diketene and aldehydes proceeded in the presence of Ti(O- i -Pr) 4 . This reaction proceeded via titanium enolate derived from Ti(O- i -Pr) 4 and diketene. As for the stereoselectivity of the products, E -isomers were produced predominantly in the case of aromatic aldehydes.