Influence of H‐Donor and Temperature on the Stereoselectivity of Radical Reactions

The successful exploitation of radicals in syntheses necessitates a detailed knowledge of the stereoselectivity of their reactions. With the vinyl radical 1 as example it can be shown how this is achieved by variation of the radical trapping agents (H donors; c ‐C 6 H 11 HgH, Bu 3 SnH, c ‐C 6 H 12 ). Below the isoselective temperature the stereoselectivity increases with decreasing rate of formation of the products. In H‐abstractions the less stable ( Z )‐alkenes are formed.