A. Kuhl et W. Kreiser, Preparation of 17 beta-(hydroxymethyl)-3-methoxyestra-1,3,5(10)-trien-18-oic acid 18,20-lactone, a new C(18)-oxygenated steroid, HELV CHIM A, 81(12), 1998, pp. 2264-2269
Lactone 13 was synthesized by intramolecular radical-mediated oxygenation o
f the angular Me(18) group of the 17 beta-configurated sterol 3. Several su
bstrate-controlled methods for stereoselective construction of the hydroxym
ethyl side chain of 3 were investigated.