A convenient, NMR-based method for the analysis of diastereomeric mixtures of pseudoephedrine amides.
نویسندگان
چکیده
Amides of pseudoephedrine and ephedrine are shown to undergo highly stereospecific, invertive cyclization to form 4,5-dihydro-3,4-dimethyl-5-phenyl-1,3-oxazolium triflate derivatives in the presence of triflic anhydride-pyridine. 1H NMR spectra of the unpurified reaction products are remarkably clean, with sharp, well-defined peaks, and allow for rapid assessment of the diastereomeric purities of the starting amides. [reaction: see text].
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ورودعنوان ژورنال:
- Organic letters
دوره 9 2 شماره
صفحات -
تاریخ انتشار 2007