Journal of Chemical Crystallography

, Volume 49, Issue 3, pp 193–205 | Cite as

Anhydrides of Arylfuran and Arylpyran Pseudoacids: Formation and Structures; C–O Bond Lengths Trends in Pseudo o-Formylbenzoic Acid Derivatives

  • Emily O’Loughlin
  • Edward J. ValenteEmail author
Original Paper


Three methods for producing anhydrides of arylfuran and arylpyran pseudoacids were explored. These included thermal dehydration, phosgene or thionly chloride activation and decomposition, and dicyclohexylcarbodiimide activation and coupling. Derivatives of the cyclic forms of o-formylbenzoic acid, o-acetylbenzoic acid, 2-carboxyphenylacetaldehyde and of 4,4-dimethyl-3,4-dihydro-3-hydroxy-[1H]-isobenzopyran-1-one were formed including dipseudoanhydides and normal-pseudo anhydrides. Crystal and molecular structures for meso and (R,R/S,S)-bis(1[3H]-isobenzofuranone-3-yl)ether, (R,R/S,S)-bis(3-methyl-1[3H]-isobenzofuranone-3yl)ether, meso (3,4-dihydro-[1H]-isobenzopyran-1-one-3-yl)ether, 3-benzoyloxy-1[3H]-isobenzofuranone, 3-benzoyloxy-3-methyl-1[3H]isobenzofuranone, 3-(4′-nitrobenzoyloxy)-4,4-dimethyl-3,4-dihydro-[1H]-isobenzopyran-1-one, and (1[3H]-isobenzofuranone-3-yl)(4,4,dimethyl-3,4-dihydro-[1H]-isobenzopyran-1-one-3-yl)ether are reported. Endocyclic pseudoacyl C–O bonds are always longer than the exocyclic pseudoacyl C–O bonds. It is possible to refine the previously established C–O bond length dependencies on the pKa (of the conjugate acids) of the leaving groups for 3-substituted 1-[3H]-isobenzofuranones. Of six dipseudoanhydrides studied, conformations are found with exocyclic C–O(ether) linkages synclinal to the endocyclic C–O and away from the ring (exo conformation) in two meso structures, two of three RR/SS forms and in a chiral unsymmetrical form. An endo conformation is observed in one of the RR/SS forms. In three normal-pseudo anhydrides, both endo and exo conformations are observed.

Graphic Abstract

Synthetic methods for formation of anhydrides of several arylfuran and arylpyran pseudoacids are described, and the pseudoacyl C–O bond length trends are determined for leaving groups spanning over 30 pKa units.


Pseudoacids Anhydrides Coupling reactions C–O bonds Bürgi-Dunitz angle 



We thank Marilyn Brooks, Brian MacFarland, Derek Thomas Letort for early synthetic explorations. EJV thanks the National Science Foundation for support of crystallographic equipment (MRI-0604188).


  1. 1.
    Mowry DT (1950) Mucochloric acid. I. Reactions of the pseudo acid group. J Am Chem Soc 72:2535–2537CrossRefGoogle Scholar
  2. 2.
    Valente EJ, Martin SB, Sullivan LD (1998) Pseudoacids. II.: 2-Acylbenzoic acid derivatives. Acta Crystallogr A B54:264–276CrossRefGoogle Scholar
  3. 3.
    Valters RE, Flitsch W (1985) In: Katritzy AR (ed) Ring-chain tautomerism. Plenum Press, New YorkCrossRefGoogle Scholar
  4. 4.
    Jones PR (1963) Ring-chain tautomerism. Chem Rev 63(5):461–487CrossRefGoogle Scholar
  5. 5.
    Wolf L (1885) Zur Kenntniss der Terpene und der ätherischen Oele. Annalen 229:258Google Scholar
  6. 6.
    Bredt J (1886) Über Acetyllävulinsäure und die Constitution der γ-Ketonsäuren. Annalen 236:225–240CrossRefGoogle Scholar
  7. 7.
    Supinski M, Valente EJ (2016) Mucochloric pseudoanhydrides. J Chem Crystallogr 46:263–268CrossRefGoogle Scholar
  8. 8.
    Weinges K, Hepp M, Huber-Patz U, Irngartinger H (1987) Chemie der Ginkgolide, III. Bilobalid/iso-Bilobalid – Strukturbeweis durch Röntgenbeugung. Liebigs Ann Chem 12:1079–1085CrossRefGoogle Scholar
  9. 9.
    Lalancette RA, Vanderhof PA, Thompson MW (1990) 2-Benzoylbenzoic acid: structures and hydrogen-bonding patterns of the anhydrous and hydrated form. Acta Crystallogr A C46:1682–1686Google Scholar
  10. 10.
    Bhatt MV, Kamath KM, Ravindranathan M (1971) Aspects of tautomerism. Part II. Reactions of the pseudo-acid chloride of o-benzoylbenzoic acid with nucleophiles. J Chem Soc C. Google Scholar
  11. 11.
    Demaison J, Csaszar AG (2012) Equilibrium CO bond lengths. J Mol Struct 1023:7–14CrossRefGoogle Scholar
  12. 12.
    Briggs AJ, Glenn R, Jones PG, Kirby AJ, Ramaswamy P (1984) Bond length and reactivity. Stereoelectronic effects on bonding in acetals and glucosides. J Am Chem Soc 106:6200–6206CrossRefGoogle Scholar
  13. 13.
    Jones PG, Kirby AJ (1984) Simple correlation between bond length and reactivity. Combined use of crystallographic and kinetic data to explore a reaction coordinate. J Am Chem Soc 106:6207–6212CrossRefGoogle Scholar
  14. 14.
    Ruggiero G, Thaggard AL, Valente EJ, Eggleston DS (1990) Structural variations in 3,4-dihydro-2H-pyran ketals: acyl and aryl warfarin derivatives. Acta Crystallogr A B46:629–637CrossRefGoogle Scholar
  15. 15.
    Cooper WJ, Smith TN, Barker AK, Webb JA, Valente EJ (2003) Pseudoacids. III. Formation and structures of new cyclic oxocarboxylic acids. J Chem Crystallogr 33(5–6):375–382CrossRefGoogle Scholar
  16. 16.
    Schöpf C, Kühn R (1950) Notiz über 2-Oxy-hydrindon-(1). Chem Ber 83:390–394CrossRefGoogle Scholar
  17. 17.
    Sheldrick GM (2008) A short history of SHELX. Acta Crystallogr A A64:112–122CrossRefGoogle Scholar
  18. 18.
    Li W, Yin H, Wen L, Li K, Fan W (2009) 3,3′-Oxybi[isobenzo-furan-1(3H)-one]. Acta Crystallogr E 65:o2577CrossRefGoogle Scholar
  19. 19.
    Letort DT (2000) Synthetic methods towards pseudoacid derivatives. Honors Essay, Mississippi College, ClintonGoogle Scholar
  20. 20.
    Valente EJ, Fuller JF, Ball JD (1998) Pseudoacids I: 4- and 5-oxoacids. Acta Crystallogr A B54:162–173CrossRefGoogle Scholar
  21. 21.
    Bürgi H-B, Dunitz JD (1994) Structure correlations, vol 2. VCH Publishers, WeinheimCrossRefGoogle Scholar
  22. 22.
    Bürgi H-B, Dunitz JD, Lehn JM, Wipff G (1974) Stereochemistry of reaction paths at carbonyl centers. Tetrahedron 30(12):1563–1572CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of ChemistryUniversity of PortlandPortlandUSA

Personalised recommendations