A novel synthesis of 2,4,6-trithiaheptane and its conversion into 2,6-bis(methylthio)thiane. Spectral properties of some thiaalkanes

Abstract

2,4,6-Trithiaheptane (1a) has been prepared by lithium tetrahydridoaluminate reduction of the methiodide of 1,3,5-trithiane (2). Treatment of 1a with strong bases permitted formation of 3-alkylated derivatives (3) which could in turn be converted into diastereomeric mixtures of 3,5-dialkyl derivatives (4). A two-step alkylation of 1a with 1-bromo-3-chloropropane led to the formation of 2,6-bis(methylthio)thiane (5). Proton and 13C nmr spectral studies on these compounds, including the measurement of long-range carbon–proton coupling constants, are described; their mass spectra showed elimination of methanethiol as a characteristic major fragmentation pathway.

The preparation, spectral properties, structures, and base-induced cleavage reactions of some α-halo-β-ketosulfones

“…375-376 and references therein). We had previously reported sizeable 3-bond carbon-proton couplings across sulfenyl sulfur (19). Such couplings have apparently not been reported across sulfonyl groups and we have not observed them previously.…”

“…We have been unable to obtain 16 in a pure form; the best chlorination conditions involved chlorination with sulfuryl chloride in acetic acid -methylene chloride and the products were shown by nmr spectroscopy to be 16, always contaminated with about 20% of its regioisomer, 17. Chlorination of 10 in the presence of triethylamine gave the unstable dichlorocompound 18, which could be saponified readily to dichloromethyl phenyl sulfone (19).…”

“…Parameters from these spectra, which were recorded under conditions described previously (19), are given in Table 1. The chemical shifts of carbons in all the compounds studied fall within acceptable ranges but several observations are noteworthy.…”

“…Infrared spectra were run in chloroform solution on a P-E 237 spectrometer. Other details have been reported previously (19). All "C spectral results are collected in Table 1; conditions for recording spectra have been reported previously (19).…”