A clean and efficient synthesis of 5-(2 '-fluoro-2 ',3 '-dimethylbutan-3 '-yl) substituted 1,2,4-oxadiazoles using silver tetrafluoroborate as a fluorodesulfurization reagent

5-Ethylthio-6,6,7,7-tetramethyl substituted 4-oxa-1,3-diazabicyclo[3.2.0]he pt-2-enes undergo fluorodesulfurization with silver tetrafluoroborate to fu rnish high yields of 5-(2'-fluoro-2',3'-dimethylbutan-3'-yl) substituted 1, 2,4-oxadiazoles. Ethylthio substituted 1,2,4-triaza- and 1,3-diaza-bicyclo[ 3.2.0]hept-2-enes behave in a similar fashion to yield 5-(2'-fluoro-2',3'-d imethylbutan-3'-yl) substituted 1,2,4-triazoles and imidazoles, respectivel y. (C) 2000 Elsevier Science S.A. All rights reserved.