2,7-diacetyl-9,9-di-n-pentyl-9H-fluorene 、
丁酸酐 在
boron trifluoride diacetate 作用下,
以31%的产率得到4-[7-(2,2-Difluoro-6-propyl-1-oxa-3-oxonia-2-boranuidacyclohexa-3,5-dien-4-yl)-9,9-dipentylfluoren-2-yl]-2,2-difluoro-6-propyl-1-oxa-3-oxonia-2-boranuidacyclohexa-3,5-diene