Ring C closure as key step in the synthesis of steroids

Steroid syntheses using Torgov syntheses, Michael additions and cyclisations, aldol cyclisation, polyene cyclisations, Friedel-Crafts cyclisations, Witting seactions, McMurray reactions, Dieckmann cyclisation, Diels-Alder cyclisations, electrocyclisations, radical cyclisation and Mukaiyama chemistry for the construction of Ring C are reviewed. The report contains 170 references.