Aziridinyl tosylhydrazones

V-acylaziridine-2-imides to oxazoline-4-imides, followed by hydrolysis of these latter compounds, has been used586 to afford chiral / -hydroxy-a-amino acid precursors. It has been suggested587 that the observed thermal rearrangement of c/.s-aziridinyl ketone tosylhydrazones (449) to 5-alkylamino-3,5-diphenyl-l-tosyl-2-pyrazolines (450) is... 

Aziridinyl-imines may be considered to be masked diazo-compounds they are cleaved thermally without the addition of external base, and thus have an advantage over tosylhydrazones as precursors of diazoalkanes."" Thermolysis of the tosylhydrazone salt of (233) at 120 °C gave a high yield of (235), and it was proposed that (234) was the intermediate. This pathway was confirmed by the thermolysis of (236) at 80 °C, which gave (234) (75%). 

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