Enantioselective Allylation of beta-Haloacrylaldehydes: Formal Total Syntheses of Pteroenone and Antillatoxin
2016
Abstract
A comparative study of the catalytic allylations and crotylations of (E)-and (Z)-haloacrylaldehydes by Lewis bases (chiral N,N'-dioxides) and Bronsted acids (chiral phosphoric acids) was undertaken. The reactions proceeded with high enantio- and diastereoselectivities with slightly better asymmetric induction observed in the case of N,N'-dioxide catalysis.
The formed enantioenriched chiral unsaturated haloalcohols could be considered general building blocks, as they could be used in the syntheses of more complex natural products possessing substituted 1,3-diene fragments. This was exemplified by the formal total syntheses of pteronenone and antillatoxin.