A rapid route to medium to large ring lactones via the thermolysis of dispiro-1,2,4-trioxane derivatives
Abstract
Dispiro-1,2,4-trioxane derivatives 3, on thermolysis in decane at 190 °C, afford either oxalactones 4, or ketolactones 5, or mixtures of both as the predominant ring-expansion products depending on the respective natures of the dispiro substituents.