Further studies on the synthesis of 24(S),25-epoxycholesterol. A new, efficient preparation of desmosterol

Thomas A. Spencer, Dansu Li, Jonathon S. Russel, Nicholas C. O. Tomkinson, Timothy M. Willson

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Efforts to improve the synthesis of 24(S),25-epoxycholesterol from stigmasterol have included identification of 6α-hydroxy-i-steroid (I) (R1 = OH, R2 = αOH) as a byproduct from the ozonolysis of steroid (II) and an attempt to effect conversion of sulfone I (R1 = SO2Ph, R2 = βOMe) (III) to diol (IV) via Payne rearrangement and nucleophilic trapping of (S)-2-hydroxymethyl-3,3-dimethylepoxide, which led instead to (V) (R3 = α or β OH) (97% yield). A more efficient synthesis of 24(S),25-epoxycholesterol was achieved via coupling of cuprate I (R1 = CuCNLi, R2 = βOMe) (VI) with allylic acetate H2C=CHCMe2OAc to give 73% of I (R1 = CH2CH=CMe2, R2 = βOMe) (VII), in the most efficient conversion yet of a C22 intermediate to desmosterol or its acetate.
LanguageUndefined/Unknown
Pages1919-1923
Number of pages5
JournalJournal of Organic Chemistry
Volume65
Issue number7
DOIs
Publication statusPublished - 2000

Keywords

  • desmosterol
  • 25-epoxycholesterol
  • stigmasterol

Cite this

Spencer, Thomas A. ; Li, Dansu ; Russel, Jonathon S. ; Tomkinson, Nicholas C. O. ; Willson, Timothy M. / Further studies on the synthesis of 24(S),25-epoxycholesterol. A new, efficient preparation of desmosterol. In: Journal of Organic Chemistry. 2000 ; Vol. 65, No. 7. pp. 1919-1923.
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abstract = "Efforts to improve the synthesis of 24(S),25-epoxycholesterol from stigmasterol have included identification of 6α-hydroxy-i-steroid (I) (R1 = OH, R2 = αOH) as a byproduct from the ozonolysis of steroid (II) and an attempt to effect conversion of sulfone I (R1 = SO2Ph, R2 = βOMe) (III) to diol (IV) via Payne rearrangement and nucleophilic trapping of (S)-2-hydroxymethyl-3,3-dimethylepoxide, which led instead to (V) (R3 = α or β OH) (97{\%} yield). A more efficient synthesis of 24(S),25-epoxycholesterol was achieved via coupling of cuprate I (R1 = CuCNLi, R2 = βOMe) (VI) with allylic acetate H2C=CHCMe2OAc to give 73{\%} of I (R1 = CH2CH=CMe2, R2 = βOMe) (VII), in the most efficient conversion yet of a C22 intermediate to desmosterol or its acetate.",
keywords = "desmosterol , 25-epoxycholesterol , stigmasterol",
author = "Spencer, {Thomas A.} and Dansu Li and Russel, {Jonathon S.} and Tomkinson, {Nicholas C. O.} and Willson, {Timothy M.}",
year = "2000",
doi = "10.1021/jo991370c",
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volume = "65",
pages = "1919--1923",
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Further studies on the synthesis of 24(S),25-epoxycholesterol. A new, efficient preparation of desmosterol. / Spencer, Thomas A.; Li, Dansu; Russel, Jonathon S.; Tomkinson, Nicholas C. O.; Willson, Timothy M.

In: Journal of Organic Chemistry, Vol. 65, No. 7, 2000, p. 1919-1923.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Further studies on the synthesis of 24(S),25-epoxycholesterol. A new, efficient preparation of desmosterol

AU - Spencer, Thomas A.

AU - Li, Dansu

AU - Russel, Jonathon S.

AU - Tomkinson, Nicholas C. O.

AU - Willson, Timothy M.

PY - 2000

Y1 - 2000

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AB - Efforts to improve the synthesis of 24(S),25-epoxycholesterol from stigmasterol have included identification of 6α-hydroxy-i-steroid (I) (R1 = OH, R2 = αOH) as a byproduct from the ozonolysis of steroid (II) and an attempt to effect conversion of sulfone I (R1 = SO2Ph, R2 = βOMe) (III) to diol (IV) via Payne rearrangement and nucleophilic trapping of (S)-2-hydroxymethyl-3,3-dimethylepoxide, which led instead to (V) (R3 = α or β OH) (97% yield). A more efficient synthesis of 24(S),25-epoxycholesterol was achieved via coupling of cuprate I (R1 = CuCNLi, R2 = βOMe) (VI) with allylic acetate H2C=CHCMe2OAc to give 73% of I (R1 = CH2CH=CMe2, R2 = βOMe) (VII), in the most efficient conversion yet of a C22 intermediate to desmosterol or its acetate.

KW - desmosterol

KW - 25-epoxycholesterol

KW - stigmasterol

U2 - 10.1021/jo991370c

DO - 10.1021/jo991370c

M3 - Article

VL - 65

SP - 1919

EP - 1923

JO - Journal of Organic Chemistry

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JF - Journal of Organic Chemistry

SN - 0022-3263

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