Oxazole Synthesis by Sequential Asmic-Ester Condensations and Sulfanyl-Lithium Exchange-Trapping

Org Lett. 2021 Feb 19;23(4):1500-1503. doi: 10.1021/acs.orglett.1c00288. Epub 2021 Feb 3.

Abstract

Oxazoles are rapidly assembled through a sequential deprotonation-condensation of Asmic, anisylsulfanylmethylisocyanide, with esters followed by sulfanyl-lithium exchange-trapping. Deprotonating Asmic affords a metalated isocyanide that efficiently traps esters to afford oxazoles bearing a versatile C-4 anisylsulfanyl substituent. Interchange of the anisylsulfanyl substituent is readily achieved through a first-in-class sulfur-lithium exchange-electrophilic trapping sequence whose versatility is illustrated in the three-step synthesis of the bioactive natural product streptochlorin.

Publication types

  • Research Support, Non-U.S. Gov't