- Practical Synthesis of (Z)-Civetone Utilizing Ti-Dieckmann Condensation
-
An efficient, practical, and stereocontrolled synthesis of (Z)-civetone (1), a representative musk perfume, has been performed utilizing a Ti-Dieckmann (intramolecular Ti-Claisen) condensation of dimethyl (Z)-9-octadecenedioate (3) as the key step. This cyclization reaction has some advantages compared with the traditional basic Dieckmann condensation such as higher concentration (100-300 mM), lower reaction temperature (0-5°C), shorter reaction time (1-3 h), use of environmentally benign (low toxicity and safe) reagents (TiCl4 and Et3N or Bu3N), and economical reagents and solvents. 15-, 17-, and 19-membered saturated β-ketoesters (6-8) were also prepared by the present method.
- Tanabe, Yoo,Makita, Atsushi,Funakoshi, Syunsuke,Hamasaki, Ryota,Kawakusu, Tetsuo
-
-
Read Online
- Processes for the preparation of macrocyclic ketones
-
Disclosed are a process of subjecting a diester of a long-chain dicarboxylic acid having 18 to 21 carbon atoms to intramolecular condensation in the presence of titanium tetrachloride or zirconium tetrachloride and a trialkylamine to form an alpha-alkoxycarbonylated macrocyclic ketone, and a process for producing a macrocyclic ketone by hydrolyzing an alpha-alkoxycarbonylated macrocyclic ketone obtained by the process and then subjecting the hydrolyzate to decarboxylation. The invention provides a process for producing a macrocyclic ketone efficiently, which permits high concentration synthesis.
- -
-
-