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Author: Subject: Is MSG useful for anything?
UnintentionalChaos
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[*] posted on 10-11-2008 at 02:00


Really? 3 membered? I would expect a dimeric 6-sided lactone to predominate by a vast majority in that case. I would not expect beta-lactones to be easy to make either but I see about gamma and delta lactones.

Sorry about my hasty posting. I tend to talk out of my ass when I see GBL or blatant cook posts.




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[*] posted on 10-11-2008 at 02:25


3-Membered rings form extraordinarily easily, alpha-lactones included. This is after all the basis of most neighbouring group assisted nucleophilic substitution, most related being those on alpha-halocarboxylic acids where retention at the chiral centre occurs due to a double SN2 (first an intramolecular yielding the alpha-lactone and then the intermolecular yielding the final product).
What is truly surprising is that this reaction actually works in the formation of 4-membered rings (beta-lactones) which are cycles that are usually harder to make (see Justus Liebigs Annalen der Chemie, 619 (1958) 47-53 and 639 (1961) 166-180 for examples of beta-lactones made this way).




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Pomzazed
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[*] posted on 10-11-2008 at 03:14


Look at this;
here's the reference of producing gamma-buterolactone-gamma-carboxylic acid from glutamic acid

http://orgsyn.org/orgsyn/prep.asp?prep=cv7p0099




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AndersHoveland
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[*] posted on 19-3-2013 at 01:28


Quote: Originally posted by guy  
How to get do you rid of the amino group?

Diazotization. NaNO2 + HBr (and heating) will substitute the amino group with a bromine group. The bromine can easily be substituted off by any nucleophile.

Ever heard of the Sandmeyer reaction?




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madscientist
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[*] posted on 26-3-2013 at 16:32


http://pubs.acs.org/doi/abs/10.1021/jo060316a

FYI, the Sandmeyer is not general to aliphatic amines, this is a special case exception.

[Edited on 27-3-2013 by madscientist]




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