e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
The Journal of Organic Chemistry
Synthesis and structure of a new stable carbocation stabilized by two neighboring sulfur atoms. Dimethyl [9, 9-bis (methylthio)-1-fluorenyl] carbenium ion
The HD exchange experiments confirm the assignments of the'H NMR signals at 6 2.70 and 1.95 (two nonequivalent C-methyls) and 2.31 (two equivalent S-methyls). This is based on the reasoning that in strong acid neither the SCH, nor the SfCH3 group undergoes HD exchange, whereas exchange is possible for the C+ CH3 group, probably via the olefin. This assignment was supported by 13C NMR data for enriched alcohol 2 (Table 111).
