Quinazolines. Part XVII. Orientation of the nitrogen lone pairs in trans-decahydroquinazolines

Abstract

The geminal coupling constants and differences in chemical shifts of the C-2 protons are used to deduce the predominant conformation of the nitrogen lone pair of electrons in trans-decahydroquinazoline (1-eq,3-eq), and its 1-methyl (1-ax,3-eq), 3-methyl (1-eq,3-ax), and 1,3-dimethyl (1-ax,3-ax) derivatives.