Title: Angelica Lactone
CAS Registry Number: 1333-38-6
CAS Name: 5-Methyl-2-furanone
Molecular Formula: C5H6O2
Molecular Weight: 98.10
Percent Composition: C 61.22%, H 6.16%, O 32.62%
Literature References: Exists in three forms. Prepn of a and b-forms: Wolff, Ann. 229, 250 (1885); Thiele, Ann. 319, 184 (1901); v. Auwers, Ber. 56, 1672 (1923); J. H. Helberger et al., Ann. 561, 215 (1949). Prepn of a¢-form: J. P. Wineburg et al., J. Heterocycl. Chem. 12, 749 (1975); V. Jäger, H. J. Günther, Tetrahedron Lett. 1977, 2543; R.A. Amos, J. A. Katzenellenbogen, J. Org. Chem. 43, 560 (1978). Toxicity data for a-form: E. J. Moran et al., Drug Chem. Toxicol. 3, 249 (1980).
Derivative Type: a-Form
Additional Names: 5-Methyl-2(3H)-furanone; D2-angelica lactone; g-methyl-b,g-crotonolactone; 4-hydroxy-3-pentenoic acid g-lactone
Properties: Volatile needles, mp 18°. d420 1.084. bp12 56°. nHe20 1.4476. One gram dissolves in 20 ml water at 15°. Heating with triethylamine soln converts it to the b-form. LD50 orally in mice: 2800 mg/kg (Moran).
Melting point: mp 18°
Boiling point: bp12 56°
Index of refraction: nHe20 1.4476
Density: d420 1.084
Toxicity data: LD50 orally in mice: 2800 mg/kg (Moran)
Derivative Type: b-Form
Additional Names: 5-Methyl-2(5H)-furanone; D1-angelica lactone; g-methyl-a,b-crotonolactone; 4-hydroxy-2-pentenoic acid g-lactone
Properties: Liquid. Not solidified at -17°. d420 1.076. bp751 208-209°. bp10 87°. nHe20 1.4603. Sol in water. Forms a dimer. More stable than a-form.
Boiling point: bp751 208-209°; bp10 87°
Index of refraction: nHe20 1.4603
Density: d420 1.076
Derivative Type: a¢-Form
Additional Names: Dihydro-5-methylene-2(3H)-furanone; g-methylene-g-butyrolactone
Properties: bp17 80°.
Boiling point: bp17 80°
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