54604-55-6Relevant academic research and scientific papers
SYNTHESIS OF HIGH SPECIFIC ACTIVITY -7-DEHYDROCHOLESTEROL. CONVERSION TO ECDYSONE IN FOLLICLE CELLS OF LOCUSTA (INSECTS)
Dolle, Frederic,Kappler, Christine,Hetru, Charles,Rousseau, Bernard,Coppo, Michele,et al.
, p. 5305 - 5316 (1990)
In previous studies we have characterized the last steps of the biosynthetic pathway of the insect moulting hormone ecdysone.We are now extending our studies to the early steps and have postulated that 7-dehydrocholesterol is one of the earliest precursor molecules.To probe this hypothesis we have synthesized this molecule under tritiated form with high specific activity (2 TBq/mmol).We have devised an original pathway which includes, as a last step, the tritiation at positions 1α and 2α.In a first series of investigations, we have demonstrated that injected 7-dehydrocholesterol was efficiently converted in vivo by the ovaries of adult females of Locusta migratoria into conjugated ecdysone and 2-deoxyecdysone.In vitro incubations of 7-dehydrocholesterol with a 1.000g supernatant of a follicle cell homogenate have occasionaly yielded conversion rates into ecdysone which were as high as 10percent.
A new synthetic method of 1α-hydroxy-7-dehydrocholesterol
Kaneko,Sugimoto,Eguchi,Yamada,Ishikawa,Sasaki,Suda
, p. 2701 - 2705 (2007/10/09)
Cholesta - 1,4,6 - trien - 3 - one (1) was converted to 3β - hydroxycholesta - 1,5,7 - triene (3) via the deconjugation procedure using t-BuOK in DMSO followed by the subsequent reduction with Ca(BH4)2. The compound (3) readily reacted with 4-phenyl-1,2,4-triazoline-3,5-dione to yield the corresponding 1,4-addition product (4). Epoxidation of 4 with m-chloroperbenzoic acid resulted in the formation of the 1α,2α-epoxide (5) and the 1β,2β-epoxide (6) in the ratio 2:3. Reduction of 5 with LAH under reflux in THF afforded the titled compound (7). The same reduction of 6 gave 2β-hydroxy- and 1β - hydroxy - 7 - dehydrocholesterol (8 and 9) in the ratio 8:1. The compound (4) can be obtained in 25% yield from 1 without any purification of the intermediate compounds; cholesta - 1,5,7 - trien - 3 - one (2, a very unstable compound) and 3. Since 1 is obtained readily from cholesterol in high yield, the present study provides a simple and efficient synthetic method of 1α-hydroxycholecalciferol and is reasonably expected to be applicable in the synthesis of 12,25-dihydroxycholecalciferol and the other metabolites of vitamin D3.
