June 02, 2020, 09:58:18 AM
Forum Rules: Read This Before Posting


Topic: Isolating small amounts of high molecular weight silyl ketene acetals  (Read 1866 times)

0 Members and 1 Guest are viewing this topic.

Offline 23SigmaTropic

  • Regular Member
  • ***
  • Posts: 11
  • Mole Snacks: +0/-0
Hi Everyone,

I was wondering if it's possible to isolate a silyl ketene acetal, specifically a TES, TBS or TIPS silyl ketene acetal that is also propargylic. I want to isolate it then do a Ireland Claisen/Diels-Alder cascade. I'm worried that the amine produced in the enolate formation will attack my dienophile.  I have found numerous examples in the literature of small MW SKA's, and they are usually isolated by distillation. I'm hoping to isolate a stable SKA derivative of a relatively high boiling ester that I made. My first thought would be some kind of Kughelrohr distillation, but I'm not sure if it would work because I have no  sense of what the bp would be. I'm familiar with the conditions for forming it, but isolating a small amount, say 200 mg, seems like I can't find a similar example in the literature.

Thanks!
 

Offline discodermolide

  • Chemist
  • Sr. Member
  • *
  • Posts: 5038
  • Mole Snacks: +404/-70
  • Gender: Male
    • My research history
Re: Isolating small amounts of high molecular weight silyl ketene acetals
« Reply #1 on: March 29, 2016, 02:10:39 AM »
Well chemistry is an experimental science. Try it and see.
Kugelrohr seems a reasonable approach. Which amine did you use? Check its BPt under vacuum.
Development Chemists do it on Scale, Research Chemists just do it!
My Research History

Sponsored Links