I really don’t understand why the following reaction would take place first of all. octahydroazecine

So this is a sub part of a question wherein we have to compare the basicity of the compounds formed through some reactions. So, I got the rest 3 of them but I have no clue about this one.

My concerns are..

  • Why would $\ce{I2}$ react in absence of any oxidising agent or catalyst?
  • Should the presence of $\ce{N}$ influence the reaction.

  • Is this reaction feasible?

Ans - alpha iodo decalin

  • $\begingroup$ You don't need an oxidizing agent, as the iodine I2 is the oxidant you are looking for. And the Nitrogen atom is necessary, because it has an available doublet. $\endgroup$ – Maurice Feb 2 at 14:21
  • $\begingroup$ @Maurice Thanks for the response but it does answer my question. First of all in halogens iodine does not react with alkenes directly ( I have been taught this , in simple words it's difficult to force it to react )...it can react in presence of a solvent or such like THF or some others .. ( I found this while doing some research) ..but since none of them is here why would it react ...and moreover what is the mechanism of the reaction? $\endgroup$ – Muskaan Feb 2 at 15:31
  • 1
    $\begingroup$ If you think iodine does not react with alkenes you have been misled - it does. The solvent should have been specified but the presence of a solvent in this reaction is taken as read. $\endgroup$ – Waylander Feb 2 at 15:40
  • $\begingroup$ What would be the mechanism ..? π complex formation like in the case of Cl2 .. and should the solvent be non polar ..@waylander $\endgroup$ – Muskaan Feb 2 at 18:50
  • $\begingroup$ Formation of an iodonium ion [3] intermediate. This reaction will occur in most solvents due to the presence of a very good internal nucleophile. $\endgroup$ – Waylander Feb 2 at 21:12

Chlorination and bromination of alkenes are very general reactions, and mechanistic study of these reactions provides additional insight into electrophilic addition reactions of alkenes. Although much less detail is known about fluorination and iodination of alkenes, it is believed that iodination follows the similar mechanistic steps of much studied bromination (Ref.1) to give corresponding 1,2-diiodoalkane. In certain compounds, if neucleophilic center is available within vicinity of cyclic halonium center, the last step of nucleophilic attack of halide ion would be over written by much faster intramolecular cyclization as depicted by following mechanism:

Azadecaline formation

This mechanism is well supported by the examples provided in Ref.1 and Ref.2.


  1. Yoshinao Tamaru, Masato Mizutani, Yutaka Furukawa, Shinichi Kawamura, Zenichi Yoshida, Kazunori Yanagi, Masao Minobe, “1,3-Asymmetric induction: highly stereoselective synthesis of 2,4-trans-disubstituted γ-butyrolactones and γ-butyrothiolactones,” J. Am. Chem. Soc. 1984, 106(4), 1079-1085 (https://doi.org/10.1021/ja00316a044).
  2. Yvan Guindon, François Soucy, Christiane Yoakim, William W. Ogilvie, Louis Plamondon, “Diastereoselective Synthesis of 2,3,5-Trisubstituted Tetrahydrofurans via Cyclofunctionalization Reactions. Evidence of Stereoelectronic Effects,” J. Org. Chem. 2001, 66(26), 8992-8996 (https://doi.org/10.1021/jo010873r).
| improve this answer | |
  • $\begingroup$ Much of what I anticipated... Thanks for the clarification. $\endgroup$ – Muskaan Feb 4 at 2:56
  • $\begingroup$ So only the rate of reaction in affected if the reaction occurs with I2 ... $\endgroup$ – Muskaan Feb 4 at 2:57

Not the answer you're looking for? Browse other questions tagged or ask your own question.