SYNTHESIS AND REACTIONS OF (4,5-DICARBOMETHOXY-1,3-DITHIOLYL)TRIBUTYLPHOSPHONIUM TETRAFLUOROBORATE

The title phosphonium salt (7) is readily prepared by the reaction of dimethyl acetylenedicarboxylate and fluo-roboric acid with the adduct of carbon disulfide and tributylphosphine and serves as a stable precursor of the corresponding unstable phosphorane (6). A comparative study of the use of salt 7 in the Wittig reaction with various aldehydes and ketones is described. Attempts to effect the complete dehydrogenation of the bisfulvene 21 from cyclo-hexane-l, 4-dione were unsuccessful. © 1979, American Chemical Society. All rights reserved.