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Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes
Published on: September 12, 2018
Convenient preparative method for lactones from 3-hydroxy propanoic acids using iodine under solvent-free conditions
Yoshio Kasashima1, Tadasuke Nishida, Hiroshi Fujimoto
1Education center, Faculty of engineering, Chiba Institute of Technology, Narashino-shi, Chiba, Japan. yoshio.kasashima@it-chiba.ac.jp
Journal of Oleo Science
|September 28, 2007
Summary
Iodine catalyzes the solvent-free intramolecular cyclization of 3-hydroxy acids to form lactones. This efficient method yields complex structures like propella lactone with skeletal rearrangement.
Area of Science:
- Organic Chemistry
- Green Chemistry
Background:
- Intramolecular cyclization of hydroxy acids is a key reaction for lactone synthesis.
- Solvent-free reactions offer environmental and economic benefits.
Purpose of the Study:
- To investigate iodine-catalyzed intramolecular cyclization of 3-hydroxy acids under solvent-free conditions.
- To explore the synthesis of complex lactones, including propella lactone, spiro lactones, bicyclic lactones, and terpenic lactones.
Main Methods:
- Utilizing iodine as a catalyst for heterogeneous intramolecular cyclization.
- Employing solvent-free conditions at 80 degrees C with a 1:0.1 hydroxy acid to iodine molar ratio for 6 hours.
Main Results:
- Efficient synthesis of lactones from 3-hydroxy acids with yields over 75%.
- Successful synthesis of propella lactone (11-oxatricyclo[4.4.3.0(1,6)]tridecan-12-one) in 88% yield, featuring carbon skeleton rearrangement.
- Efficient synthesis of terpenic lactones from camphor, fencone, and pulegone derivatives, also with skeletal rearrangement.
Conclusions:
- Iodine is an effective catalyst for solvent-free intramolecular cyclization of 3-hydroxy acids.
- The developed method provides a green and efficient route to various complex lactones, including those with skeletal rearrangements.
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