CAS No 118-71-8 , 3-hydroxy-2-methylpyran-4-one

Title: Maltol
CAS Registry Number: 118-71-8
CAS Name: 3-Hydroxy-2-methyl-4H-pyran-4-one
Synonyms: 3-hydroxy-2-methyl-4-pyrone; 3-hydroxy-2-methyl-g-pyrone; larixinic acid; palatone; veltol
Molecular Formula: C6H6O3
Molecular Weight: 126.11
Percent Composition: C 57.14%, H 4.80%, O 38.06%
Literature References: Found in the bark of young larch trees (Larix decidua Mill.), in pine needles (Abies alba Mill., Pinaceae), in chicory, in wood tars and oils, in roasted malt. Isoln from these sources and structure: Kiliani, Bazlen, Ber. 27, 3115 (1894); Feuerstein, Ber. 34, 1804 (1901); Erdmann, Schaefer, Ber. 43, 2398 (1910); Reichstein, Beitter, Ber. 63, 824 (1930), cf. Peratoner, Tamburello, Chem. Zentralbl. 76, II 680 (1905). Also obtained by alkaline hydrolysis of streptomycin salts: Schenck, Spielman, J. Am. Chem. Soc. 67, 2276 (1945). Synthesis: Spielman, Freifelder, ibid. 69, 2908 (1947); Chawla, McGonigal, J. Org. Chem. 39, 3281 (1974). Novel high-yield synthesis: T. M. Brennan et al., Tetrahedron Lett. 1978, 331; P. D. Weeks et al., J. Org. Chem. 45, 1109 (1980). History and comparison with isomaltol: Hodge, Nelson, Cereal Chem. 38, 207 (1961).
Properties: Monoclinic prisms from chloroform, orthorhombic bipyramidal crystals + monoclinic prisms from 50% alcohol, mp 161-162°. Fragrant, caramel-like odor. Begins to sublime at 93°. Volatile with steam. uv max (0.1N HCl): 274 nm (Em 8400); (0.1N NaOH): 317 nm (Em 7300). pH of 0.5% aq soln 5.3. One gram dissolves in 85 ml water. Freely sol in hot water, chloroform; sol in alcohol; sparingly sol in benzene, ether, petr ether; sol in aq alkali hydroxides giving yellow solns.
Melting point: mp 161-162°
Absorption maximum: uv max (0.1N HCl): 274 nm (Em 8400); (0.1N NaOH): 317 nm (Em 7300)
Use: Flavoring agent, to impart "freshly baked" odor and flavor to bread and cakes.