Biomimetic synthesis of 5,6-dihydro-glaucogenin C: construction of the disecopregnane skeleton by iron(II)-promoted fragmentation of an α-alkoxy hydroperoxide.

A skeleton key: A biomimetic synthesis of the title natural product was completed in 19 steps and 6.4% overall yield. Iron(II)-promoted fragmentation of α-alkoxy hydroperoxide and subsequent trapping of the resulting tertiary carbon radical by iodide enabled the highly efficient construction of the challenging 13,14:14,15-disecopregnane skeleton (see scheme; TBDPS=tert-butyldiphenylsilyl). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.