Neighboring methoxyl participation in the acid catalyzed methoxylation of methylene-interrupted fatty acids.
The boron trifluoride-methanol derivatization of methyl 9,12-octadecadienoate was studied. This methylene-interrupted diene was reacted with 50% BF3-MeOH for 15 h at 0-5 degrees C and the four monomethoxy and two dimethoxy derivatives thus obtained were analyzed by gas chromatography-mass spectrometry. The only dimethoxy adducts observed were characterized as methyl 9,12-dimethoxyoctadecanoate and methyl 10,13-dimethoxyoctadecanoate. The complete regiospecificity observed in the formation of the dimethoxy adducts is best explained by a common O-methyltetrahydrofuranium ion as the only intermediate under these reaction conditions.
Carballeira
N M
NM
Department of Chemistry, University of Puerto Rico, San Juan 00931-3346. ncarball@upracd.upr.clu.edu
González
M V
MV
Pagán
M
M
D002384:Catalysis; D005227:Fatty Acids / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006838:Hydrocarbons; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry
D005227:Fatty Acids; D006838:Hydrocarbons; C030011:carbene; D008697:Methane