Remember I showed you a successful crystallization of a chiral material a while ago? Probably not. It was almost three years ago. Damn. This is the old post I am talking about.

Just wanted to tell you that I am today at liberty to show you the exact structures! Our scale-up story recently hit the press.

(S)-Taniguchi lactone

Org. Process Res. Dev. 2014, Article ASAP (DOI: 10.1021/op500096j)

Asymmetric synthesis is great for publishing in high-impact journals. Under circumstances process chemists often refer to as “real chemistry”, however, fanciness has little if any bearing. Cost of manufacture – that is the deal-breaker in production. This concept is largely unheard of in grad school. Maybe that should change. What do you think?

 

8 Responses to In a 200 L reactor…

  1. Chemjobber says:

    I enjoyed the article!

  2. Maybe you’ve still got any e-reprints available? Unfortunately, I have no access.

  3. How do they extract with 50×3 L CH2Cl2 in industry? Or what about drying 150 L over sodium sulphate? Do I ask stupid questions? :)

    • Chemjobber says:

      The first is easy, you pump it in, stir it for the recommended time, stop to let the layers settle and drain through the bottom valve. (Assuming, of course, that you have a good split and no emulsions.)

      As for the drying over sodium sulfate, I was wondering that myself. (There are plenty of ways to do it. As long as you have a safe means of getting the solid into a reactor/tank and getting it stirred, that is.) Dr. Freddy?

  4. milkshake says:

    I think a better way would be to do kinetic asymmetric hydrolysis of monoepoxide of butadiene (Eastman makes itons of it), with Jacobsen Cr-salen catalyst and water (neat, 0 C to room temp), distill out the optically pure epoxide straight from the reaction flask. Then take that and open it with Li-enolate of tBuOAc, and cyclize in situ with acid. It would be just two steps, and the rejection of the unwanted enantiomer would happen during the first step, while the molecular weight of the material is still low.

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