137435-98-4Relevant academic research and scientific papers
[3,3]-Claisen rearrangements in 24α-methyl steroid synthesis: Application to campesterol, crinosterol, and Δ25-crinosterol side chain construction
Khripach, Vladimir A.,Zhabinskii, Vladimir N.,Konstantinova, Olga V.,Khripach, Natalya B.,Antonchick, Andrey P.,Schneider, Bernd
, p. 597 - 603 (2007/10/03)
This paper elaborates an improved synthesis of crinosterol and campesterol starting from stigmasterol. The proposed approach is based on Claisen rearrangement of Δ23-22-allylic alcohols with various configurations of the 22-hydroxy group and ge
Biosynthetic studies of marine lipids. 39.1 19-norsterols: The course of c-19 methyl elimination
Rabinowitz, Michael H.,Djerassi, Carl
, p. 304 - 317 (2007/10/02)
The biosynthesis of 19-norstanols in the Mediterranean sponge, Axinella polypoides, was investigated through the use of radiotracer experiments. It was found that the conversion of cholesterol (7) to 19-nor-5α-chotestan-3β-ol (8) involved oxidation at C-3 with the distribution of the abstracted hydride from the 3α-position of dietary cholesterol into all of the 19-norstanols of the native mixture. Furthermore, while the efficiency of conversion of Δ5-19-oxygenated sterol precursors 19-hydroxycholesterol (9) and 3β-hydroxycholest-5-en-19-oic acid (10) to 8 was low, the efficiency of the conversion of 19-hydroxycholest-4-en-3-one (23) to 8 was high, suggesting that the principal pathway for 19-norstanol biosynthesis involves oxidative isomerization of a dietary Δ5-3β-hydroxy sterol to the δ4-3-ketone before oxidation at C-19. It was also shown that the conversion of cholesterol to 19-nor-5α-cholestan-3β-ol involves the stereospecific loss of the 4β-hydrogen atom. It was further determined that the biological demethylation pathway is suppressed for dietary sterols bearing an unconventional configuration at C-20 in the hydrocarbon side chain.
