A. Budzowski, A. Linden, H. Heimgartner
Dec 31, 2004
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Influential Citations
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Journal
Heterocycles
Abstract
The hydrolysis of methyl N-(2,2-dimethyl-2H-azirin-3-yl)-L-prolinate (1c) at 50°C in the presence of silica gel afforded (S)-perhydro-3,3-dimethylpyrrolo[1,2-a]pyrazine-1,4-dione ((S)-4a), which was thionated chemoselectively to give the corresponding 1-thioxo derivative ((RS)-5a) as a racemic mixture. On the other hand, treatment of 1c with hydrogen sulfide led to the 4-thioxo isomer ((S)-6a). Thionation with Lawesson reagent yielded the bisthioxo compound ((RS)-7a), again as a racemate. Analogous reactions were carried out with the heterospirocyclic N-(2H-azirin-3-yl)-L-prolinates (1d) and (1e). The structures of (RS)-5a, (S)-6a-c, and (RS)-7a have been established by X-Ray crystallography.