Revised structures for the adducts of ergosteryl acetate with maleic anhydride

Jones, David; Greenhalgh, P.F.; Thomas, I.

doi:10.1016/0040-4020(68)89031-3

Cited by 9 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Product yields were determined by quantitative HPLC analyses. It is interesting to note that the distributions of adducts obtained from reaction of 1 with the series of N-aryl maleimides are very similar to that reported for the reaction of 2 with maleic anhydride (14).…”

supporting

confidence: 58%

“…Eviphiles such as dialkyl azocarboxylates (1-3), dimethyl acedently, Diels-Alder addition is preferred only with particularly powerful dienophiles such as N-phenyltriazolinedione (7,8), 1,4-phthalazinedione (9), or singlet oxygen (lo), or with acyclic alkenes when the steroidal diene moiety is part of a higher conjugated system (1 1). The reaction of maleic anhydride with ergosteryl acetate, which was first investigated almost 60 years ago (12), has been the subject of some confusion over the years (12)(13)(14). The reaction is now known to yield a mixture of the ene and Diels-Alder adducts shown in eq.…”

Section: Introductionmentioning

confidence: 99%

“…[ l ] (14). The structures of the four products (3-5) have been assigned on the basis '~a t u r a l Sciences and Engineering Research Council of Canada University Research Fellow, 1983-1993.…”

Section: Introductionmentioning

confidence: 99%

“…of derivativization studies and 'H NMR spectroscopy (14), following the pioneering studies of Huisman and co-workers on the reactions of dienophiles with 7-dehydrocholesteryl acetate (1) (1, 3). As part of our continuing studies of the effects of thermotropic liquid crystals on the reactivity of guest molecules (1 5), we have investigated the reaction of 1 with a series of N-aryl maleimides (6-8).…”

Section: Introductionmentioning

confidence: 99%

“…As shown in the partial structures below, differentiation of the two adduct structures is possible if the protons at C-1 1, C-12, C-15, and C-9/14 can be rigorously identified. We also employed these methods to establish the stereochemistry in the Diels-Alder adduct 11, in order to verify the assignment made by Jones et al for the DielsAlder adduct (3) obtained from the reaction of ergosteryl acetate (2) with maleic anhydride (14).…”

mentioning

confidence: 99%

See 4 more Smart Citations

Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

Leigh¹,

Hughes²,

Mitchell³

1992

Can. J. Chem.

View full text Add to dashboard Cite

Thermolysis of N-phenyl, N-para-biphenyl, and N-para, para′-terphenylmaleimide with 7-dehydrocholesteryl acetate in benzene solution at 200 °C yields mixtures of four cycloadducts in relative yields that are essentially independent of the maleimide substituent. The three major products are those of ene addition to C7 of the steroid with abstraction of the proton at C9 or C14. The α-endo-Diels-Alder adduct is formed as a minor product. The structures of the adducts have been elucidated on the basis of one- and two-dimensional 1H and 13C NMR spectroscopic techniques, including homonuclear 1H decoupling, NOE, 1H–1H COSY, heteronuclear 1H–13C shift correlation, and TOCSY 2-D experiments, and the results of molecular mechanics (MMX) calculations. The combination of these techniques has made it possible to almost completely assign the 1H and 13C NMR spectra for two of the ene adducts and the Diels–Alder adduct from reaction of 7-dehydrocholesteryl acetate with N-phenyl maleimide.

show abstract

supporting

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

Leigh¹,

Hughes²,

Mitchell³

1992

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

Ansa‐Seco‐Steroide

et al. 1987

View full text Add to dashboard Cite

show abstract

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

Kircher

Rosenstein

1975

Lipids

View full text Add to dashboard Cite

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.

show abstract

Revised structures for the adducts of ergosteryl acetate with maleic anhydride

Cited by 9 publications

References 12 publications

Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

Ansa‐Seco‐Steroide

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

Contact Info

Product

Resources

About