NEW MATERIAL:A compound expressed by the formula (X is H or Cl).
EXAMPLE: 2,2-Dichloro-3-(2-chloro-2-methylethyl)-4-hydroxybutyrolactone.
USE: An intermediate for preparing cis-chrysanthemumic acid.
PREPARATION: Prenyl alcohol expressed by formula II is reacted with trichloroacetyl chloride (CCl3COCl) in a solvent, e.g. benzene, in the presence of a weakly basic catalyst, e.g. pyridine, at -5W+10°C to give almost quantitatively a compound expressed by formula III, which is then reacted with cuprous chloride in a solvent, e.g. acetonitrile, at 120W160°C to cause free radical cyclization and give the compound expressed by formula I (X is Cl). The resultant compound expressed by formula I (X is Cl) can be treated with a tri-alkyltin hydride, etc. in the presence of a catalytic amount of azobisisobutyronitrile, etc. at 70W 100°C to remove selectively Cl in the α-position.
OGASAWARA KUNIROU
AKIYAMA MASAJI
