Enantioselective Aldol Synthesis via Radical Addition to Cyclic Enones

Significance

The development of a chiral Lewis acid mediated radical conjugate addition to cyclic enones is reported. This versatile method provides cyclic anti-aldol products of various ring sizes in high yields and excellent diastereo- and enantio­selectivities. It constitutes not only a new example (among the rare enantioselective radical addition reactions), but also an efficient alternative to the classical aldol synthetic methods via anionic intermediates, especially for the difficult coupling of bulky aldehyde counterparts with cyclic ketones.