Convenient preparative method for lactones from 3-hydroxy propanoic acids using iodine under solvent-free conditions.
Intramolecular cyclization of 3-hydroxy acids was investigated using iodine as a catalyst under solvent-free conditions. The reaction proceeded to completion in the heterogeneous system. Lactones were obtained by intramolecular cyclization of 3-hydroxy acids. Propella lactone (11-oxatricyclo[4.4.3.0(1,6)]tridecan-12-one) was conveniently synthesized from 3-hydroxy acid ((6-hydroxyspiro[4.5]dec-6-yl)acetic acid) in 88% yield with carbon skeleton rearrangement. Spiro lactones and bicyclic lactones were also obtained from the corresponding 3-hydroxy acids in yields of over 75%. The most suitable reaction conditions were a temperature of 80 degrees C, a molar ratio of 3-hydroxy acid:iodine = 1:0.1, and a time period of 6 h. In addition, terpenic lactones were efficiently synthesized from the corresponding 3-hydroxy acids, derived from (+)-camphor, (-)-fencone, and (-)-pulegone, with skeleton rearrangement. The yield of the solvent-free reaction was as high as that of the corresponding reaction in solution.
Kasashima
Yoshio
Y
Education center, Faculty of engineering, Chiba Institute of Technology, Narashino-shi, Chiba, Japan. yoshio.kasashima@it-chiba.ac.jp
Nishida
Tadasuke
T
Fujimoto
Hiroshi
H
Mino
Takashi
T
Sakamoto
Masami
M
Fujita
Tsutomu
T
D002384:Catalysis; D007455:Iodine / Q000737:chemistry*; D019344:Lactic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D012997:Solvents
D007783:Lactones; D012997:Solvents; D019344:Lactic Acid; D007455:Iodine; C031601:hydracrylic acid