71473-15-9Relevant academic research and scientific papers
A new approach to the side chain formation of 24-alkyl-22-hydroxy steroids: Application to the preparation of early brassinolide biosynthetic precursors
Hurski, Alaksiej L.,Zhabinskii, Vladimir N.,Khripach, Vladimir A.
, p. 780 - 790 (2012/07/03)
A new synthetic route to 22S-hydroxy-24R-methyl steroids has been developed and applied for the preparation of cathasterone, (22S)-hydroxycampesterol, and 6-deoxocathasterone, which are precursors in the early stages of the biosynthesis of brassinolide. The construction of the steroid side chain with the correct stereochemistry at C-24 is based on the use of Claisen rearrangement. The introduction of the 22-hydroxyl group has been achieved by epoxidation of the Δ22-double bond, nucleophilic opening of the intermediate mesyl epoxide with sodium sulfide, and desulfurization of the formed tetrahydrothiophenes with Raney nickel.
Stereospecificity and Regiospecificity of the Phosphorus Oxychloride Dehydration of Sterol Side Chain Alcohols
Giner, Jose-Luis,Margot, Christian,Djerassi, Carl
, p. 369 - 373 (2007/10/02)
Stigmasta-5,23(E)-dien-3β-ol (2) and stigmasta-5,23(Z)-dien-3β-ol (3), sterols of potential biosynthetic interest, were synthesized by phosphorus oxychloride dehydration.High stereospecificity and regiospecificity in this reaction is evident in the dehydrations of several steroidal side chain alcohols.A two-step hydroboration-phosphorus oxychloride dehydration procedure is described for reversing the geometry of trisubstituted double bonds.Surprisingly facile borane migration with retention of the configuration at C24 was observed in the hydroboration of steroidalside chain olefins.Phosphorus oxychloride dehydration was used to introduce deuterium into the vinylic position of isofucosterol (15) via its i-methyl ether.
