Two for one: Thermal generation of acylketenes in diol-containing substrates results in the title transformation. This transformation expands the scope of acylketene macrolactonizations and their application to the synthesis of complex macrolides. Triol and tetraol substrates have also been cyclized in highly regioselective fashion. Additionally, the challenging macrolactonization of a tertiary alcohol was achieved. (Chemical Equation Presented).
- Concerted addition