The Alkaline Hydrolysis of Fluorenone-spirohydantoin

Harris, G. H.; Harriman, B. R.; Wheeler, Keith W.

doi:10.1021/ja01209a040

Cited by 32 publications

(6 citation statements)

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“…The synthetic route is shown in Scheme 2. The resulting product, 3 is not new as the formation of the urea moiety has been previously observed [22,23]. The formation of 2 and 3 was confirmed by FTIR, NMR and X-ray analyses.…”

Section: Resultssupporting

confidence: 75%

Synthesis and Structural Characterization of Spiro(fluorene-9,4′-imidazolidine)-2′,5′-dione and (9H-Fluorene-9-yl)urea

et al. 2012

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Alkaline hydrolysis of spiro(fluorene-9,4 0 -imidazolidine)-2 0 ,5 0 -dione, 2 resulted in ring opening leading to (9H-fluorene-9-yl) urea, 3. The crystal structures 2 and 3 have been determined. Compound 2 crystallizes in the orthorhombic space group P2 1 2 1 2 1 with a = 7.2596(9) Å , b = 9.4497(14) Å , c = 17.304(3) Å and Z = 4 while compound 3 crystallizes in the monoclinic space group P2 1 /c with a = 4.6171(3) Å , b = 14.4713(9) Å , c = 16.9762(14) Å , b = 95.385(7)°and Z = 4. Both molecules have very similar bond lengths and angles pattern, even after the hydantoin ring opening. The 9H-fluorene moiety is nearly planar with rms of 0.007 and 0.032 Å for 2 and 3. The angle between the mean planes of the 9H-fluorene and the hydantoin or carbamide moieties is 86.92(4)°and 71.07(4)°respectively. In both structures N-HÁÁÁO hydrogen bonds connect molecules into the chains along a. The X-ray molecular structure and IR spectra for 2 and 3 are compared with those calculated by the density functional theory method.

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Section: Resultssupporting

confidence: 75%

Synthesis and Structural Characterization of Spiro(fluorene-9,4′-imidazolidine)-2′,5′-dione and (9H-Fluorene-9-yl)urea

et al. 2012

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“…This was first demonstrated by Tiemann, although under his aqueous alcoholic conditions it is questionable whether the aldimine or the aldehyde ammonia was the actual reagent (563). Subsequently the reaction was carried out under anhydrous conditions which precluded intermediates of the latter type (245). A number of other ketimines behave similarly (404,530).…”

Section: Rcocn + C02mentioning

confidence: 99%

“…Although it has been demonstrated that aldimines and ketimines will add hydrogen cyanide to give a-aminonitriles (245,404,563), it seems improbable that this intermediate is formed in an aqueous mixture of the three reagents under mild conditions.…”

Section: Cn Ho Cnmentioning

confidence: 99%

The Preparation of Nitriles.

Mowry¹

1948

Chem. Rev.

392

103

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“…The classical Bü cherer -Berg method could not be used for the synthesis of the free amino acid H-Afc-OH, as the alkaline hydrolysis of the spirohydantoin from 9-fluorenone leads to the decarboxylated product 9-fluorenylurea [29]. DuPriest et al synthesized the ester H-Afc-OMe by treatment of a 9-fluorenone Schiff base anion with methylchlorocarbonate [24].…”

Section: Peptide Synthesismentioning

confidence: 99%

Synthesis, conformational study, and spectroscopic characterization of the cyclic Cα,α-disubstituted glycine 9-amino-9-fluorenecarboxylic acid

et al. 1999

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A series of terminally blocked peptides (to the pentamer level) from L-Ala and the cyclic C alpha, alpha-disubstituted Gly residue Afc and one Gly/Afc dipeptide have been synthesized by solution method and fully characterized. The molecular structure of the amino acid derivative Boc-Afc-OMe and the dipeptide Boc-Afc-Gly-OMe were determined in the crystal state by X-ray diffraction. In addition, the preferred conformation of all of the model peptides was assessed in deuterochloroform solution by FT-IR absorption and 1H-NMR. The experimental data favour the conclusion that the Afc residue tends to adopt either the fully-extended (C5) or a folded/helical structure. In particular, the former conformation is highly populated in solution and is also that found in the crystal state in the two compounds investigated. A comparison with the structural propensities of the strictly related C alpha, alpha-disubstituted Gly residues Ac5c and D phi g is made and the implications for the use of the Afc residue in conformationally constrained analogues of bioactive peptides are briefly examined. A spectroscopic (UV absorption, fluorescence, CD) characterization of this novel aromatic C alpha, alpha-disubstituted Gly residue is also reported.

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The Alkaline Hydrolysis of Fluorenone-spirohydantoin

Cited by 32 publications

References 0 publications

Synthesis and Structural Characterization of Spiro(fluorene-9,4′-imidazolidine)-2′,5′-dione and (9H-Fluorene-9-yl)urea

Synthesis and Structural Characterization of Spiro(fluorene-9,4′-imidazolidine)-2′,5′-dione and (9H-Fluorene-9-yl)urea

The Preparation of Nitriles.

Synthesis, conformational study, and spectroscopic characterization of the cyclic Cα,α-disubstituted glycine 9-amino-9-fluorenecarboxylic acid

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