Using the non-selective nature of acetoacetic ester synthesis and malonic ester synthesis to produce cyclic compounds

As has been discussed previously – acetoacetic ester synthesis and malonic ester synthesis are non-selective, in that, they can produce dialkylated products. This particular property of these reactions can be made use of to synthesize cyclic compounds using a alkyl dihalide. This reaction can be used to even produced highly strained 4-membered rings as is shown below.

Steps:

  1. In presence of base and alkyl dihalide, the beta-keto ester or malonic ester can react to produce the substituted compound. (note – increasing the alkyl chain length would yield bigger cyclic structures, and R1 can be either alkyl or ester)
  2. Since base is still present and one of the halides is still present on the product itself, the disubstitution leads to formation of a ring. (note- chances of another alkyl dihalide from reacting with this product is lesser compared to the alkyl halide which is already attached to it).
  3. Once the cyclic compound is formed the reaction need not stop there – the product can undergo hydrolysis under the basic conditions to yield the acid (at this stage if R1 is also an ester it may undergo hydrolysis).
  4. Finally acidification with slight heating may promote the compound to lose 1 molecule of carbon dioxide to yield the product.
Using the non-selective nature of acetoacetic ester synthesis and malonic ester synthesis to produce cyclic compounds
Using the non-selective nature of acetoacetic ester synthesis and malonic ester synthesis to produce cyclic compounds

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References

  1. Advanced Organic Chemistry: Reactions and synthesis. By Francis A. Carey, Richard J. Sundberg
  2. Organic-Chemistry.org (accessed on February 06, 2011)

This Post Has 3 Comments

  1. Christopher

    I came across your web in error but I am glad I did! I am grateful for the details.

  2. Akul Mehta

    It is a little difficult to judge what you are trying to make. Please draw the structure and show me so that I may help you.

  3. Reband

    I need your help, please could you tel me how can we prepare the same molecule with five carbon in the ring and have one double bond in the bottom?
    I will be appreciate if you could reply me soon your subject very important to me.

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