梯形烷

梯形烷（英文：ladderane），又稱梯烷，是一種含有兩個或多個稠合四元環的環烷烴。它的英文名ladderane是一個混成詞，因為四元環的排列形狀類似於梯子，並且是一種烷烴。有n個環的梯形烷化學式為C_2n+2H_2n+6。梯形烷的空間構型張力很大，因為碳原子上的配體不能使用正常的鍵角來成鍵。然而，梯形烷的例子已經在生物體內被發現。^[1] 一個典型的例子是五環厭氧氨氧化酸（Pentacycloanammoxic Acid），^[2] 它由五個稠合的環丁烷單元構成。它在細菌中進行厭氧氨氧化過程，這使得它形成了緊且厚的膜，這阻止了生物體失去肼中間體。後者參與了氮的產生和亞硝酸根離子與氨反應生成水。^[3]

梯形烷可以由碳碳雙鍵到單鍵的還原反應製得，同時伴隨著新碳碳鍵的形成並關環。^[1]^[4]

參考資料

[1]
Nouri, D H, Tantillo, D J. They Came from the Deep: Syntheses, Applications, and Biology of Ladderanes. Curr. Org. Chem. 2006, 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. Linearly concatenated cyclobutane lipids form a dense bacterial membrane. Nature. 2002, 419 (6908): 708–712. PMID 12384695. doi:10.1038/nature01128.
[3]
Vincent Mascitti and E. J. Corey. Enantioselective Synthesis of Pentacycloanammoxic Acid. J. Am. Chem. Soc. 2006, 128 (10): 3118. PMID 16522072. doi:10.1021/ja058370g.
[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: COMP 247.

Henning Hopf. "Chains, rings, substituents: Tales from the marvelous edifice of modern organic chemistry." Lecture at the 234th American Chemical Society National Meeting in Boston, MA on Tuesday, August 21, 2007, 2:45 to 3:30 PM.
Ladderane lipids website, UC Davis （頁面存檔備份，存於網際網路檔案館）

參見

[nouri-a-1] [1]
Nouri, D H, Tantillo, D J. They Came from the Deep: Syntheses, Applications, and Biology of Ladderanes. Curr. Org. Chem. 2006, 10 (16): 2055–2074. doi:10.2174/138527206778742678.

[2] [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. Linearly concatenated cyclobutane lipids form a dense bacterial membrane. Nature. 2002, 419 (6908): 708–712. PMID 12384695. doi:10.1038/nature01128.

[3] [3]
Vincent Mascitti and E. J. Corey. Enantioselective Synthesis of Pentacycloanammoxic Acid. J. Am. Chem. Soc. 2006, 128 (10): 3118. PMID 16522072. doi:10.1021/ja058370g.

[nouri-b-4] [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: COMP 247.

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