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Updated: May 12, 2025

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines
Published on: January 3, 2018
1,2-Acyl transposition through photochemical skeletal rearrangement of 2,3-dihydrobenzofurans
Ryan T Steele1, Motohiro Fujiu1, Richmond Sarpong1
1Department of Chemistry, University of California, Berkeley, CA, USA.
Abstract:
Saturated heterocycles are commonly adorned with groups that influence their biological properties. Synthetic methods that transpose existing substituents on saturated heterocycles to multiple peripheral positions are therefore highly valuable. In this work, we report a formal 1,2-acyl transposition through the photochemical exchange of the C2-C3 positions of C2-acylated dihydrobenzofurans. This strategy relies on an unusual photochemical isomerization of the dihydrobenzofuran core to a highly electrophilic spiro-cyclopropane intermediate that is then intercepted by a halide nucleophile. A variety of aryl ketones are transposed using 370-nanometer centered irradiation. Additionally, carboxylic acids, esters, and amides can be transposed using 310-nanometer centered irradiation. This work highlights the power of a skeletal rearrangement to achieve a net peripheral modification.
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