Some unusual transformations of a highly reactive α-bromocaranone

The facile synthesis of a highly reactive α-bromocaranone from (+)-carene is reported. This intermediate was found to generate diverse chiral building blocks through radical or carbocation mediated cyclopropyl fragmentation reactions in moderate to excellent yields. Furthermore, the formation of an unexpected carvone derivative prompted several control studies that provided mechanistic insight into an unusual transformation. This study not only demonstrates the synthesis of a variety of chiral building blocks but provides insight into the reactivity of keto-halo-cyclopropanes in general.