10.1021/ol402301g.s001 Jens Cordes Jens Cordes Philip R. D. Murray Philip R. D. Murray Andrew J. P. White Andrew J. P. White Anthony G. M. Barrett Anthony G. M. Barrett 1,7-Diazaspiro[5.5]undecane – A Neglected Heterocycle American Chemical Society 2013 spirocyclic adducts alkyl halides spirocyclization decarboxylation Claisen condensation spiroaminal Neglected HeterocycleA Diazaspiro step synthesis complex alkane dihalides novel bidentate ligand electrophile tetrahydropyridine derivatives ruthenium acid chlorides diazaspiro sulfonyl chlorides parent heterocycle 2013-10-04 00:00:00 Dataset https://acs.figshare.com/articles/dataset/1_7_Diazaspiro_5_5_undecane_A_Neglected_Heterocycle/2370322 A convenient and simple three step synthesis of 1,7-diazaspiro[5.5]undecane via Claisen condensation and acid catalyzed decarboxylation and spirocyclization of <i>N</i>-Boc-δ-valerolactam is described. Reactions of this spiroaminal with electrophiles including alkyl halides, alkane dihalides, acid chlorides, and sulfonyl chlorides gave either spirocyclic adducts or tetrahydropyridine derivatives. Additionally, the parent heterocycle is a novel bidentate ligand and formed complexes with ruthenium(II) and copper(II).