From: Eugen Leitl (eugen$##$leitl.org)
Date: Tue Jun 06 2006 - 10:01:21 EDT
On Mon, Jun 05, 2006 at 04:01:39PM -0400, Kiessling, Dr Anthony J wrote:
> I agree with others that is a pretty bold statment for post-docs to make. I had an experience in grad. school trying to reproduce a published procedure. At the time I needed a compound and the literature source I used (Perkins Tranactions if I remember right) was the only source at the time for that particular compound. Anyway, the lit. claimed a 45% yield during one particular step in the synthesis. The step for anyone who is curious was a Dieckmann cyclization that yielded a bicyclic compound. Well, I tried the step and got a 20% yield. Tried again same result. I was able to contact the person who actually did the work and found out that they did publish their best yield not their average yield which for them was 30%. I needed to push a lot of material through and had limitations on equipment so I did the reaction several times. My best yield overall almost matched the literature value. Moral of the story: 1) try to find more than one recipe from the literature if you can; 2) try the reaction a few times before you claim the procedure doesn't work; 3) If it still doesn't work contact the authors and find out who actually ran the reaction there may be a tid-bit of information about technique that is often very had to convey in the literature. As was also mentioned remember that no one tests synthetic procedures to see if they work with the one exception of Organic Syntheses where all procedures are tested by a separate lab group to verify the claims of the authors.
>
Not to forget -- frequently publications deliberately omit
critical information, in order for the group to maintain the
lead. Cherry-picking data (publishing best yields) is also routine.
This is similiar to patents: the description contains
just enough information to secure the claim, but deliberately
obfuscates everything else in order to making recreating the
invention as difficult as possible.
-- Eugen* Leitl leitl http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE
_______________________________________________
ORGLIST - Organic Chemistry Mailing List
Website / Archive / FAQ: http://www.orglist.net
To post a message (TO EVERYBODY) send to everybody$##$orglist.net
To unsubscribe, send to everybody-request$##$orglist.net the message: unsubscribe your_orglist_password your_address
This archive was generated by hypermail 2.1.4 : Tue Feb 13 2007 - 14:17:01 EST