One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping

A one-pot gamma-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation /oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the gamma-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.

Automated summary

A highly efficient one-pot gamma-lactonization of homopropargyl alcohols has been developed via an alkyne deprotonation/boronation/oxidation sequence. The oxidation of alkynyl boronate leads to the formation of ketene intermediate, which then reacts with the adjacent hydroxy group to produce the gamma-lactone. Optimization of conditions and exploration of substrate scope and synthetic applications have been conducted for this efficient one-pot lactonization reaction.