Spektroskopische Untersuchung der Wasserstoffbrücken in Spiro[4,4]nonandiolen

The infrared absorption of three stereoisomeric spiro[4,4]‐nonanediols‐(1,6) in the 3000/cm region is discussed. The trans ‐ trans diol does not show internal hydrogen bonds, whereas the cis ‐ trans and the cis ‐ cis isomers exhibit one internally bonded hydroxy group. From the existence of these hydrogen bonds it is concluded that both the five membered carbon rings of the spiro‐nonane frame are noticeably puckered. In the cis ‐ cis compound the puckering is produced by oxygen‐oxygen repulsion forces, in the cis ‐ trans compound by the hydrogen bond energy.