120. Steroids and related compounds. Part II. The dehydration of cholestanetriol

Petrow, Vladimir; Rosenheim, Otto; Starling, W. W.

doi:10.1039/jr9380000677

Cited by 27 publications

(3 citation statements)

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“…This was accomplished by acetylation followed by continuous development TLC, which separates A7-from 5a-sterol acetates. Only the former grouip was present in H. heterophyllus, and( it gave the expecte(l positive color reactions in the TortelliJaffe (14) and seleniiulm dioxide (9) tests. TLC on Anasil B (1, 3) separated the A7-sterol acetate fraction into 2 components, corresponding in molbilities to A 7-stigmasten-3,8-ol acetate an( A 722-stigmastadien-3,8-ol (a-spinasterol) acetate.…”

Section: Resultsmentioning

confidence: 99%

Time Course of Steroid Biosynthesis and Metabolism in Haplopappus heterophyllus

Bennett¹,

Lieber²,

Heftmanń³

1967

Plant Physiol.

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Summiiiiiary. A single dose of mevalonic acid-2-14C was administered simultaneously to 6 Haplopapppus heterophyllu(s plants. They were harvested at intervals ranging from 3 days to 6 months. Four groups of biosynthetically related sterols were found to be radioactive in each plant, and the changes in radioactivity with time were studied. The most striking finding was a radioactive phenolic material present only in the 6-month plant, which had flowered. The solvent was evaporated in vacuum, and the residue was then refluxed with a mixture of 25 ml of benzene, 55 ml of water, and 20 ml of concentrated hydrochloric acid for 3 hours. The benzene layer was separated, and the aqueouis layer was extracted with 2 25-ml portions of dichloromethane. The organic layers were washed with 15 ml of water, filtered, combined, an-d evaporated. The residue was taken up in 25 ml of benzene and extracted with 2 15-ml portions of 2 % sodium bicarbonate solution and 15 ml of watcr. The extracts were passed through 10 ml of benzene and discarded. The original benzene layer was then extracted with 2 15-ml portions of 0.5 N sodium hydroxide and 15 ml of water. The extracts were passed through the same 10 ml of benzene as above, filtered, combined, and immediately acidified with concentrated hydrochloric aciid. The mixture was then extracted with 2 25-ml portions of dichloromethane, and the extracts were passecd through 10 ml of water, filtered, comibined, and evaporated (Phenolic Fraction).The original benzene layer from above was combined with that used for washing the aqueous extracts, filtered, and evaporated. The residue was 973 www.plantphysiol.org on May 11, 2018 -Published by Downloaded from

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Section: Resultsmentioning

confidence: 99%

Time Course of Steroid Biosynthesis and Metabolism in Haplopappus heterophyllus

Bennett¹,

Lieber²,

Heftmanń³

1967

Plant Physiol.

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“…It has been demonstrated (2,5,8) that certain 5a-hydroxy-6/3-acetoxy-steroids are converted to the corresponding 4 6-unsaturated-6/3-acetoxy-compounds by treatment with thionyl chloride in pyridine. Treatment of 3/3-methoxy-5ahydroxy-6/3-acetoxycholestane (III) in this way produced a crystalline substance, m.p.…”

Section: H3cmentioning

confidence: 99%

The Preparation of 3β-Methoxy-5-Methyl-10-Nor-8(9)-Cholestene, an Isomer of Cholesteryl Methyl Ether

Shealy¹,

Dodson²

1951

J. Org. Chem.

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Petrovv (1-3) has demonstrated that treatment of 3/3,6/S-diacetoxy-5a-hydroxycholestane (I) with sulfuric acid in acetic anhydride resulted in dehydration and rearrangement to a molecule formulated as 3/3,6/3-diacetoxy-5-methyl-10-nor-8(9)-cholestene (IV), More recently, 3/3,6/3-diacetoxy-5-methyl-10-nor-8( 9)-androsten-17-one and certain of its derivatives (4, 5) have been prepared by the rearrangement of 3 ß, 6/3-diacetoxyandrostan-5o:-ol-17-one. These rearranged androstenes proved to be physiologically inactive, and it was speculated that this lack of activity may be due to the presence of the 6-acetoxyor 6-ketogrouping in the molecule. 6-Ketotestosterone possesses no androgenic activity (8). In this paper, the preparation of 3/3-methoxy-5-methyl-10-nor-8 (9) -cholestene (IX), an isomer of cholesteryl methyl ether, is reported. The methods used 1427 SUMMARY 3/J-Methoxy-5-methyl-10-nor-8(9)-cholestene, an isomer of cholesteryl methyl ether, was prepared from cholesteryl methyl ether by a series of reactions involving hydroxylation of the double bond, rearrangement of the C-10 methyl group to C-5, and removal of the oxygen function at C-6. Minneapolis 14, Minnesota

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“…

The Westphalen rearrangement is an example of the 'backbone' rearrangement of steroids. 1,2 The C-10β methyl group migrates to C-5 when a C-5α alcohol is dehydrated with sulfuric acid. The C-10 carbocation is discharged with the formation of a 9(10)-alkene.

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confidence: 99%