
TY  - JOUR
A1  - Aasen, AJ 
A1  - Culvenor, CCJ 
A1  - Willing, RI 
T1  - Shielding of H7&#946; in pyrrolizidine derivatives
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1971
VL  - 24
IS  - 12
SP  - 2575
EP  - 2580
KW  - 
UR  - https://doi.org/10.1071/CH9712575 
N2  - The conformations of 3-oxopyrrolizidine derivatives are discussed on the basis of an analysis of the nuclear magnetic resonance spectrum of 3,5-dioxopyrrolizidine and partial data for methyl 2,3- dioxopyrrolizidine-1-carboxylate and methyl 2&#946;-hydroxy-3- oxopyrrolizidine-1a-carboxylate. In each compound, H 7&#946; is located forward into the fold of the rings and is subject to a shielding influence which is thought to be due to the C 8-C 1 single bond. 
ER  -

