Title:  Retene 
CAS Registry Number:  483-65-8 
CAS Name:  1-Methyl-7-(1-methylethyl)phenanthrene 
Molecular Formula:  C18H18 
Molecular Weight:  234.34 
Percent Composition:  C 92.26%, H 7.74% 
Literature References:  Occurs in pine tar, in fossilized pine, in high-boiling tar oils.  Formed by Se or Pd dehydrogenation of abietic acid:  Ruzicka, Waldmann, Helv. Chim. Acta 16, 842 (1933).  Synthesis starting with methyl b-(6-isopropyl-2-naphthoyl)propionate:  Bardhan, Sengupta, J. Chem. Soc. 1932, 2520, 2798; cf.  Bogert, Science 77, 289 (1933).  Review and bibliography:  Fieser, Fieser, Natural Products Related to Phenanthrene (New York, 3rd ed., 1949). 
Properties:  Plates, scales from alc, mp 99°.  bp10 208°; bp760 390-394°.  Absorption spectrum:  Askew, J. Chem. Soc. 1935, 509.  Insol in water.  Sol in hot alcohol, benzene, hot ether, carbon disulfide.  Upon treatment with CrO3 in acetic acid forms retenequinone, C18H16O2, mp 197.5°. 
Melting point:  mp 99°; mp 197.5° 
Boiling point:  bp10 208°; bp760 390-394°   |