Ladderane

A ladderane is an organic molecule containing two or more fused rings of cyclobutane. The name is a portmanteau because the serial cyclobutane rings look like a ladder and are singly bonded like alkanes. The chemical formula for a ladderane with n rings is C2n+2H2n+6. The geometry of ladderanes is highly strained because ligands to the carbon atoms cannot extend to their ideal angles. However, examples of ladderanes have been found in living organisms.[1] An example is pentacycloanammoxic acid[2] which is composed of 5 fused cyclobutane units. It is found in bacteria performing the anammox process where it forms part of a tight and very dense membrane believed to prevent the organism from losing the intermediate hydrazine which is involved in the production of nitrogen and water from nitrite ions and ammonia.[3]

Ladderanes can be formed by the reduction of a carbon-carbon double bond into a single bond, concomitant with the creation of a new carbon-carbon bond to close the ring.[1][4]

References

  1. ^ a b Nouri, D H, Tantillo, D J (2006). "They Came from the Deep: Syntheses, Applications, and Biology of Ladderanes". Curr. Org. Chem. 10 (16): 2055–2074. doi:10.2174/138527206778742678. 
  2. ^ J. S. Sinninghe Damsté, M. Strous, W. I. C. Rijpstra, E. C. Hopmans, J. A. J. Geenevasen, A. C. T. van Duin, L. A. van Niftrik and M. S. M. Jetten (2002). "Linearly concatenated cyclobutane lipids form a dense bacterial membrane". Nature 419 (6908): 708–712. doi:10.1038/nature01128. PMID 12384695. 
  3. ^ Vincent Mascitti and E. J. Corey (2006). "Enantioselective Synthesis of Pentacycloanammoxic Acid". J. Am. Chem. Soc. 128 (10): 3118. doi:10.1021/ja058370g. PMID 16522072. 
  4. ^ Nouri, D H and Tantillo, D J. "Ladderane Formation Mechanisms: The Uphill Battle". 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006. pp. COMP 247. 

See also