“…However, only few papers have dealt with their synthesis, − and the structures of only two compounds have been determined by single-crystal X-ray diffraction. ,, On the other hand, it is well-known that hypercoordinated group 14 elements derivatives display a wide range of biological activity, which makes them interesting for medicinal chemistry and pharmacology. ,, Thus, spirobis(ocanes) ( III ) may also be potentially useful as therapeutic agents. As a part of our program to investigate the structure and chemical behavior of hypercoordinated germanium molecules, especially germatranes and germocanes, and to compare the degree of strength of the transannular M←N interactions with those in the derivatives of other main group elements, ,− we present the synthesis of three novel 1,7,9,15-tetraoxa-4,12-diaza-8-germaspiro[7.7]pentadecanes, i.e., [RN(CH 2 CHR‘O) 2 ] 2 Ge ( 1 − 3 ), which are the derivatives of N -methyldiethanolamine ( 4 ), N -methyl- N -(2-hydroxy-2-phenylethyl)ethanolamine ( 5 ), and N -phenyldiethanolamine ( 6 ), respectively. The motivation in our work was to study structural changes in hypercoordinated germanium compounds arising from the replacement of substituents at the different positions of the ligand cage.…”