Radikalinduzierte intramolekulare 1, 4‐Verschiebung einer Formylgruppe

Abstract

Radical‐induced Intramolecular 1,4‐Transfer of a Formyl Group A further example of a radical‐induced intramolecular shift of a functional group in steroids is described. In analogy to the sequence leading to the 1, 4‐transfer of cyano groups [3], 11 β‐nitrite photolysis was used to generate the appropriate C (18) radical in the 20‐hydroxy‐11 β‐nitrosyloxy‐pregnene‐21‐al 6 . Intramolecular addition of the radical center to the double‐bond of the specially adjacent aldehyde function, followed by fragmentation of the intermediate cyclic alkoxy radical and subsequent oxidation lead directly to the rearranged 18‐formyl compound 10 .