Reference

Search for REF=[7155].

7155
Peterson, D. H., Murray, H. C., Eppstein, S. H., Reineke, L. M., Weintraub, A., Meister, P. D. and Leigh, H. M.
Microbiological transformations of steroids. I. Introduction of oxygen at carbon-11 of progesterone.
J. Am. Chem. Soc. 74: 5933-5936, 1952.
DOI: 10.1021/ja01143a033.