In this Letter we report on the reaction of 4H-cyclopenta[2,1-b:3,4- b′]dithiophen-4-one with various trivalent organophosphorus derivatives, with an emphasis on the final products depending on the applied reagents. No reaction occurred upon treatment with either triphenyl- or tricyclohexylphosphine, whereas addition of triethyl phosphite or tri(n-butyl)phosphine resulted in pinacol rearrangement. Structure elucidation of the isolated 5H-spiro(benzo[1,2-b:6,5-b′]dithiophene-4,4′- cyclopenta[2,1-b:3,4-b′]dithiophen)-5-one was achieved by combined NMR experiments, theoretical chemical shift and geometry calculations, and single crystal X-ray analysis.
Bibliographical noteFunding Information:
We gratefully thank BELSPO in the frame of the IAP P6/27 and IAP 7/05 networks. Y. Z. acknowledges the financial support of the Fonds Spéciaux de Recherche of the Académie Universitaire Louvain, co-funded by the Marie Curie Actions of the European Commission (ADi/DB/986.2011). The calculations were performed on the Interuniversity Scientific Computing Facility (ISCF), for which we acknowledge financial support from the FRS-FRFC (Convention No. 2.4.617.07.F) and from the University of Namur.
- Chemical shift calculations
- Pinacol rearrangement
- Trivalent organophosphorus reagents
- X-ray diffraction
ASJC Scopus subject areas
- Drug Discovery
- Organic Chemistry