Ja. Boynton et al., STEREOCHEMISTRY OF THE TETRACYANOETHYLENE-CATALYZED METHANOLYSIS OF STEROIDAL EPOXIDES, Journal of chemical research. Synopses, (8), 1995, pp. 334-335
In contrast to simpler systems, the methanolysis of the epimeric C-4 a
nd C-5 steroidal epoxides catalysed by tetracyanoethylene is shown to
have a regiochemistry dominated by the trans periplanar relationship b
etween the resultant alkoxy and hydroxy groups.