Rearrangement-Driven Molecular Diversity: Synthesis of Functionalized Pyrones, Orthoesters, and Xanthones from Spiroketals

Maddali L N Rao; Sk Shamim Islam

doi:10.1021/acs.orglett.1c02888

Rearrangement-Driven Molecular Diversity: Synthesis of Functionalized Pyrones, Orthoesters, and Xanthones from Spiroketals

Org Lett. 2021 Nov 19;23(22):8668-8672. doi: 10.1021/acs.orglett.1c02888. Epub 2021 Oct 29.

Authors

Maddali L N Rao¹, Sk Shamim Islam¹

Affiliation

¹ Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.

PMID: 34714091
DOI: 10.1021/acs.orglett.1c02888

Abstract

The reaction of tricyclic 5,5-benzannulated spiroketals with trifluoroacetic acid (TFA) and AlCl₃ furnished benzopyranobenzopyrans, benzofuro-orthoesters, and benzofuroxanthones. Whereas the reaction of tricyclic 5,5-benzannulated spiroketals with TFA produced the pyrones, the reaction with AlCl₃ furnished densely functionalized orthoesters and xanthones. The formation of these products was rationalized by fascinating mechanistic pathways involving semipinacol/α-ketol molecular rearrangements.

Publication types

Research Support, Non-U.S. Gov't