Title: Muscone
CAS Registry Number: 541-91-3
CAS Name: 3-Methylcyclopentadecanone
Additional Names: muskone; methylexaltone
Molecular Formula: C16H30O
Molecular Weight: 238.41
Percent Composition: C 80.61%, H 12.68%, O 6.71%
Literature References: The odorous principle of musk. Characterization of naturally occurring (-)-form: Ruzicka, Helv. Chim. Acta 9, 715 (1926). Structure: ibid. 1008. Synthesis of (±)-form: Ziegler, Weber, Ann. 512, 164 (1934); Ruzicka, Stoll, Helv. Chim. Acta 17, 1308 (1934); Hunsdiecker, Ber. 75B, 1197 (1942). Review of syntheses: S. Abe et al., Cosmet. Perfum. 88, 67 (1973). Recent syntheses: Stork, Macdonald, J. Am. Chem. Soc. 97, 1264 (1975); H. G. Fliri et al., Monatsh. Chem. 110, 245 (1979); C. Fehr et al., Helv. Chim. Acta 62, 2655 (1979); K. H. Schulte-Elte et al., ibid. 2673; G. Cantoni et al., J. Org. Chem. 45, 1906 (1980). Chiral synthesis of (R)-(-)- and (S)-(+)-forms: Q. Branca, A. Fischli, Helv. Chim. Acta 60, 925 (1977).
Derivative Type: (-)-Form
Properties: Oily liquid. Musk odor. bp 328°; bp0.5 130°. d417 0.9221. nD17 1.4802. [a]D17 -13°. Very slightly sol in water; miscible with alc.
Boiling point: bp 328°; bp0.5 130°
Optical Rotation: [a]D17 -13°
Index of refraction: nD17 1.4802
Density: d417 0.9221
Derivative Type: (±)-Form
Properties: Oily liquid. bp0.01 90°. nD26 1.4767. uv max (ethanol): 285 nm (log e 1.54).
Boiling point: bp0.01 90°
Index of refraction: nD26 1.4767
Absorption maximum: uv max (ethanol): 285 nm (log e 1.54)
Musks Mustard Muzolimine Mycaminose Mycarose

CAS number 10403-00-6 N
Jmol-3D images Image 1
Molecular formula C16H30O
Molar mass 238.40 g/mol
Density 0.9221 g/cm3
Melting point −15 °C; 5 °F; 258 K
Boiling point 328 °C; 622 °F; 601 K
NFPA 704
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Muscone is an organic compound that is the primary contributor to the odor of musk.

The chemical structure of muscone was first elucidated by Lavoslav Ružička. It consists of a 15-membered ring ketone with one methyl substituent in the 3-position. It is an oily liquid that is found naturally as the (−)-enantiomer, (R)-3-methylcyclopentadecanone. Muscone has been synthesized as the pure (−)-enantiomer as well as the racemate. It is very slightly soluble in water and miscible with alcohol.

Natural muscone is obtained from musk, a glandular secretion of the musk deer, which has been used in perfumery and medicine for thousands of years. Since obtaining natural musk requires killing the endangered animal, nearly all muscone used in perfumery today is synthetic. It has the characteristic smell of being "Musky". One asymmetric synthesis of (−)-muscone begins with commercially available (+)-citronellal, and forms the 15-membered ring via ring-closing metathesis:[1]

Synthesis of muscone via RCM

A more recent enantioselective synthesis involves an intramolecular aldol addition/dehydration reaction of a macrocyclic diketone.[2] Muscone is now produced synthetically for use in perfumes and for scenting consumer products.