Bis-enolates with extended π-conjugation are powerful nucleophiles. Study of their alkylation reactions with very hindered C-electrophiles

Abstract

Bis-enolates with extended π-conjugation, prepared by alkali metal-mediated reduction of several aromatic and unsaturated diesters, can be efficiently and regioselectively alkylated with very hindered C-electrophiles, such as neopentyl, secondary and tertiary alkyl halides, and tosylates. A one-step synthesis of 4-alkyl phthalates was derived from the reductive alkylation of a phthalate diester with hindered halides followed by rearomatization with oxygen. Additionally, synthetic protocols have been developed to efficiently prepare complex fused- or spiro-bicycles from diisopropyl phthalate in just one or two steps