The synthesis of 13,14-seco steroids starting from easily available (13S)-13-iodo-6-methoxy-3,5-cyclo-13,14-seco-5-androsta-14,17-dione is described. The C-17 ketone was converted regioselectively into its oxime with simultaneous stereoselective deiodination at C-13. The remaining C-14 carbonyl group was then reduced stereoselectively with Ca(BH4)2. The configurations at the relevant stereocenters of the thus obtained hydroxy oxime were determined by X-ray analysis. Successful regeneration of the C-17 carbonyl group was achieved by treatment of the corresponding oxime acetate with TiCl3.
- medium-sized ring
Khripach, V. A., Zhabinskii, V. N., Kuchto, A. I., Fando, G. P., Zhiburtovich, Y. Y., Lyakhov, A. S., Govorova, A. A., Groen, M. B., van der Louw, J., & de Groot, Æ. (2004). Reaction of (13S)-13-iodo-6beta-methoxy-3alpha,5-cyclo-13,14-seco-5alpha-androstane-14,17-dione with hydroxylamine and its application to the synthesis of new 13,14-seco steroids. Steroids, 69(7), 511-514. https://doi.org/10.1016/j.steroids.2004.04.006