Understanding the Synthesis and Stereochemistry of Benzoxazoles from Ketene Dithioacetals

Benzoxazoles constitute a highly relevant class of heterocyclic compounds due to their significant applications in the biological sciences. Ketene dithioacetals serve as versatile substrates for double vinylic substitution reactions, enabling the synthesis of various heterocyclic frameworks, including benzoxazoles. In this context, an integrated experimental and theoretical study was conducted to explore the synthesis of benzoxazoles from ketene dithioacetals, with particular emphasis on evaluating the scope of the methodology and elucidating aspects of stereochemistry. The structure and stereochemistry of compound 15 were unambiguously confirmed by single‐crystal X‐ray diffraction analysis, which revealed the presence of the E‐isomer configuration.