THREE-DIMENSIONAL STRUCTURES OF 1-ACYL-5-HYDROXYPYRAZOLIDINES

Article abstract of DOI:10.1007/BF00515031

It was shown by x-ray diffraction analysis and PMR spectroscopy that 1-acyl-5-hydroxy- and -5-hydrazinopyrazolidines have a conformation with an axial orientation of the functional group attached to the C(₅) atom.The 1-salicylyl derivatives constitute an exception: in methanol solutions they exist in a conformation with an equatorial hydroxy group, whereas in dimethylformamide (DMF) the ring undergoes partial opening to give the corresponding β-hydrazido aldehydes.