1796. Carbic Anhydride

Nomenclature

CAS number: 129-64-6
3aα,4,7,7aα-Tetrahydro-4α,7α-methanoisobenzofuran-1,3-dione; cis-endo-5-norbornene-2,3-dicarboxylic anhydride; endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride; 3,6-endo-methylene-1,2,3,6-tetrahydro-cis-phthalic anhydride; 3,6-endo-methylene-Δ4-tetrahydrophthalic anhydride; nadic anhydride.
C9H8O3; mol wt 164.16.
C 65.85%, H 4.91%, O 29.24%.

Description and references

Prepd by the reaction of maleic anhydride with cyclopentadiene in benzene: Diels, Alder, Ann. 460, 98 (1928). Crystal structure: Destro et al., Acta Crystallogr. 25B, 2465 (1969).

Chemical structure

Properties

Shiny, orthorhombic crystals from petr ether, mp 164-165°. d 1.417. Converted to equilibrium mixtures with exo-cis isomers when heated above mp. Sol in benzene, toluene, acetone, carbon tetrachloride, chloroform, ethanol, ethyl acetate. Slightly sol in petr ether. Reacts with water to form the corresponding acid. Forms the γ-lactone of 5-hydroxy-2,3-norcamphanedicarboxylic acid in 50% H2SO4.