Here is a one-step transformation that I think few, perhaps not even Corey,* would come up with upon a traditional retrosynthetic analysis.

A and B

A and B are everyday organic reagents. The solvent is DCM and the temperature is around 0 °C. No metals, complexes or weird oxidation level crap. So – go ahead and name A and B!

Remember I have this Stuxnet 3.5 beta spyware installed on all of your computers that smell out and report the use of SciFinder and Reaxys. Likewise through your webcam, Vogel, March, Paquette and Larock are detected, to name a few.

Kudos to FA, my fellow grad student, who back in the days included this example in his thesis (also recognized by my software).

* Retract that. Corey would have.


7 Responses to Name A and B!

  1. Ed says:

    Had to think about it for a while: A is obviously the 1,2-Ethanedithiol. The Dithiolan should then migrate when the cyclohexane ring is aromatized with B in this case maybe with a strong Lewis Acid?

  2. Martyn says:

    Must be an oxidant along with the dithiol – I’ll go for NCS.

    • drfreddy says:

      We have a winner! The original recipe called for 1,2-ethanedithiol and NBS, but I guess NCS would work just as fine.

      Can you see the mechanism? First the dithioacetal as expected, then oxidation/halogenation of a sulfur, ring opening to a sulfenyl halide, a bit of flipping around, more halogenation and loss of HBr and … hmpf, perhaps James over at can draw it step by step in color for us?

  3. Ed says:

    My second guess yesterday would have been bromine or iodine. Found some reference where the second step works this way but NBS is a much nicer solution 🙂

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