Direct conversion of γ,γ-dicarbonyl-substituted aldehydes into γ-lactones with a sodium chlorite/DBDMH combination

Abstract

An unprecedented and challenging simultaneous carboxylation/halogenation, and next lactonization of γ,γ-dicarbonyl-substituted aldehydes has been realized using a NaClO2/DBDMH combination.

Successive Waste as Reagent: Two More Steps Forward in a Pinnick Oxidation

“…Despite progress in designing one-pot tandem reactions that utilize byproducts, such as various inorganic salts (InCl 3 , CuI, NaF, and NaBr), Ph 3 PO, HCl, HI/I 2 , formed in the upstream step as catalyst or reagent for subsequent reactions, the use of waste ClO – formed in Pinnick oxidations as a reagent or catalyst has been rarely reported until we recently disclosed a NaClO 2 /DBDMH (1,3-dibromo-5.5-dimethylhydantoin)-mediated γ-lactonization of γ,γ-dicarbonyl-substituted aldehydes. This reaction used waste ClO – as a useful chlorinating reagent, but its efficiency was limited, and DBDMH had to be added as a cohalogenating agent (Scheme , top) . Clearly, developing a new Pinnick oxidation-initiated oxidative lactonization reaction in which waste ClO – is utilized as the only halogenating agent is highly attractive.…”

“…This reaction used waste ClO − as a useful chlorinating reagent, but its efficiency was limited, and DBDMH had to be added as a cohalogenating agent (Scheme 1, top). 7 Clearly, developing a new Pinnick oxidation-initiated oxidative lactonization reaction in which waste ClO − is utilized as the only halogenating agent is highly attractive.…”