group in the 4-position relative to the amine were 0.4 pH units more acidic than the corresponding compound with an axial OH. A similar effect was observed for the COOMe substituent. The difference in electron-withdrawing power of axial and equatorial substituents was explained by a difference in charge-dipole interactions in the two systems. Since this stereoelectronic substituenteffect causes differences
Ringschlussreaktionen des Butadiendioxids mit Hydrazinen zu neuen Derivaten des Pyrazolidins und Piperidazins
作者:H. R. Meyer、R. Gabler
DOI:10.1002/hlca.19630460727
日期:——
The reaction of butadiene dioxide (dl-and meso-) with various hydrazines led to 1: 1-adducts having either pyrazolidine or piperidazine structures. Using N,N′-di-substituted hydrazines, pyrazolidine derivatives were obtained with yields of 70–80%, whereas hydrazine itself reacted with DL-butadiene dioxide to give about 20% of trans-4,5-dihydroxypiperidazine and a small quantity of trans-7,8-tetrah