(4E,6Z)-および(4E,6E)-アロオシメンとホルムアルデヒドとのPrins反応

抄録

The Prins reaction of alloocimene with formaldehyde proceeded smoothly in dichloromethane under reflux in the presence of acetic acid. The reaction products were mainly 2- (2- methy1-1-propeny1)-4, 5-dimethyl-5, 6-dihydro-2 H-pyran [2] and trans- or cis-4, 5-dimethy1-5- (4-methyl-1, 3-pentadienyl)-1, 3-dioxan, [3] or [4]. The stereochemistry of the dioxans, [3] and [4], was also discussed on the basis of the NMR spectra. The compositions of the products were dependent on the isomer ratio of alloocimene used.