B. G.  Hazra, Kumar, T. P., and Pore, V. S., ?Stereoselective synthesis of (2R, 3S, 22R, 23E)-6, 6-ethylenedioxy-22-hydroxy-2, 3-isopropylidenedioxy-24-methyl-5 alpha-cholest-23-ene: An intermediate for the synthesis of castasterone, dolichosterone and brassinolide?, Indian Journal of Chemistry Section B-Organic Chemistry including Medicinal Chemistry, vol. 44, no. 3, pp. 611-614, 2005.