91157-15-2Relevant academic research and scientific papers
Sterochemical Aspects of Acid-Catalyzed Cyclopropane Ring-Opening Reactions. A Stereospecific Pathway to Crinosterol and Brassicasterol
Lang, Robert W.,Djerassi, Carl
, p. 407 - 418 (1982)
It is shown that the acid-catalyzed ring-opening of the two diastereoisomeric 23,24-methylenecholosterols 3 and 5 on treatment with gaseous HCl in acetic acid leads sterospecifically to the naturally occuring crinosterol (4) and brassicasterol (6), respectively (Scheme 1).This isomerization can be viewed as a biomimetic model of an in vivo methylation process of the type already known in plant sterol metabolism (cf. cycloeucalenol --> obtusifoliol, 1-->2).The synthetic application of this method provides a convenient labelling of sterol side chain for tracer experiments.The mechanistic features of the reaction with respect to its particular stereospecificity are discussed.
