Alpha-Ergostenol and Its Isomerization to Beta-Ergostenol

Speer, John H.; Heyl, Frederick W.

doi:10.1021/ja01368a042

Cited by 3 publications

(2 citation statements)

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“…147-149 °C, of specific activity 0-131 mc/mmole. [3a-3H]Ergosterol, diluted with carrier, specific activity 0-15 mc/mmole, was reduced to 3ft-hydroxyergost-8( 14)-ene by the method of H art, Speer & Heyl (1930) and then ergost-8( 14)-en-3-one was prepared by the method of Bladon et al (1951). The specific activity, 0-3 nc/mmole, corresponded to retention of 0-2% of the tritium of the original [3a-3H]ergosterol.…”

Section: R K Callow E Kodicek and G A Thompsonmentioning

confidence: 99%

Metabolism of tritiated vitamin D

Callow

Kodíček

Thompson

1966

Proc. R. Soc. Lond. B.

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Methods of labelling calciferol in specified positions with tritium have been investigated with the purpose of selecting a stable and highly radioactive compound for metabolic studies. [3 α - 3 H]Ergocalciferol and [24, 25, 26, 27- 3 H 9 ]-, [7- 3 H]-, [6- 3 H]- and [1 α - 3 H]-cholecalciferol have been prepared and the excretion and distribution in the body of vitamin D activity and radioactivity after administration to young rachitic rats has been studied. It is concluded that [1 α - 3 H]cholecalciferol is a suitable tritium-labelled form of vitamin D for further metabolic studies. The more notable results of the present studies are that much of the tritium from variously tritiated calciferols finds its way into the body water, and that break-down products of calciferol are to be found in the more polar fractions of the extracts of faeces, into which they pass from the bile.

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Section: R K Callow E Kodicek and G A Thompsonmentioning

confidence: 99%

Metabolism of tritiated vitamin D

Callow

Kodíček

Thompson

1966

Proc. R. Soc. Lond. B.

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“…The melting point was not depressed by admixture with an authentic sample of Va (m.p. 132-133°) prepared according to the method of Hart, et al (15). Hart gives m.p.…”

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confidence: 99%

THE ISOMERIZATION OF Δ^{7, 22}-ERGOSTADIENOL WITH COPPER CHROMIUM OXIDE

Nes¹,

Mosettig²

1953

J. Org. Chem.

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Nearly twenty-five years ago Reindel and Walter (1) discovered that 6 -7• 22ergostatrienyl acetate (lb, ergosteryl acetate) absorbed two moles of hydrogen when reduced in ethereal solution, with platinum black as catalyst, to give A8(lt)-ergostenyl acetate (Vb, -ergostenyl acetate). Simultaneously with the saturation of the 5,6 and 22,23 double bonds a shift of the double bond from 7,8 to 8,14 took place. The isomerization has also been effected (2) starting with A7-ergostenol (Via, -ergostenol). Despite the more recent and rather extensive investigations of this subject, notably by Wieland and Benend (3) and by Barton and co-workers (4, 5, 6), the rearrangement of the nuclear double bond has not been accomplished without hydrogenation of the side chain double bond. Indeed, the expected product, namely 8(14) • 22-ergostadienol (Ilia, ß-dihydroergosterol), has not been obtained in a pure state by any isomerization procedure. Heilbron and co-workers ( 7) and Dithmar and Achtermann (8) reported its preparation by isomerization with dry hydrogen chloride, but Barton and co-workers (6) have shown that under these conditions the product obtained is an inseparable equimolecular mixture containing the further isomerized compound, 14• 22ergostadienol.We have been able to obtain 8(14) • 22-ergostadienol (Ilia) in a 54% yield by direct isomerization of 7• 22-ergostadienoll (Ila, -dihydroergosterol) using a copper chromiun oxide catalyst (10) in the presence of hydrogen. The compound was accompanied by a crystalline by-product which probably has a 3-a-hydroxyl group. The complete structure of this latter material is under investigation. The structure of Ilia was indicated by its hydrogenation to A8(14)-ergostenol (Va) under conditions which do not normally lead to isomerization, and by the agreement of its molecular rotation with the calculated value.2 While this work was in progress, Laubach and Brunings (9c) reported the preparation of 8(14) 22-ergostadienyl acetate (Illb) by 1,2 addition of hydrogen to 6•8(14) • 22-281 spectra which have been used in this work. We also thank Mr. Robert Kostic for technical assistance. SUMMARY 1. 7-22-Ergostadienol ( -dihydroergosterol) has been isomerized in the presence of copper chromium oxide and hydrogen to 8(14) 22-ergostadienoI.2. Hydrogenation with copper chromium oxide or Raney nickel reduced the A9(11)-bond of the 7•9(u)-diene system in ergosterol-D. Bethbsda 14, Maryland

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Reaction of ergosteryl acetate with maleic anhydride and preparation of 5,7‐ergostadien‐3β‐ol

Kircher

Rosenstein

1975

Lipids

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An improved, large scale synthesis of the ergosteryl acetate-maleic anhydride Diels-Alder adduct and its pyrolysis are described. The complex mixture obtained by reaction of the two constituents was refluxed with methanol to convert the succinic anhydride derivatives, formed by the "ene" reaction, to soluble half esters, leaving the insoluble Diels-Alder adduct largely unchanged. The latter was hydrogenated and pyrolyzed in vacuo to yield 5,7-ergostadienyl acetate together with lesser quantities of the acetates of 7,9(11)-ergostadien-3beta-ol, 6,8(9)-ergostadien-3beta-ol, and 8,14-ergostadien-3beta-ol. These components were separated and purified by argentation column chromatography and crystallization.

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Alpha-Ergostenol and Its Isomerization to Beta-Ergostenol

Cited by 3 publications

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Metabolism of tritiated vitamin D

Metabolism of tritiated vitamin D

THE ISOMERIZATION OF Δ^{7, 22}-ERGOSTADIENOL WITH COPPER CHROMIUM OXIDE

Reaction of ergosteryl acetate with maleic anhydride and preparation of 5,7‐ergostadien‐3β‐ol

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Alpha-Ergostenol and Its Isomerization to Beta-Ergostenol

Cited by 3 publications

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Metabolism of tritiated vitamin D

Metabolism of tritiated vitamin D

THE ISOMERIZATION OF Δ7, 22-ERGOSTADIENOL WITH COPPER CHROMIUM OXIDE

Reaction of ergosteryl acetate with maleic anhydride and preparation of 5,7‐ergostadien‐3β‐ol

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THE ISOMERIZATION OF Δ^{7, 22}-ERGOSTADIENOL WITH COPPER CHROMIUM OXIDE