- Deconjugation of dehydroamino acids: Stereoselective synthesis of racemic (E)-vinylglycines
-
(Chemical Equation Presented) A practical and general two-step synthesis of carbamate-protected (E)-vinylglycines from aliphatic aldehydes is reported. The key step involves the kinetic α-protonation of dianionic dienolates derived from dehydroamino acids
- Alexander, Paul A.,Marsden, Stephen P.,Munoz Subtil, Dulce M.,Reader, John C.
-
p. 5433 - 5436
(2007/10/03)
-
- Synthesis and in vitro enzyme activity of aza, oxa and thia derivatives of bacterial cell wall biosynthesis intermediates
-
Mechanism based inhibitors of diaminopimelate aminotransferase (DAP-AT) were designed using knowledge of its substrate specificity and mechanism. Synthesis of thiolester and amide substrate analogues was achieved prior to in vitro inhibition studies, but ester analogues proved too unstable to isolate. Thia substrate analogues showed no inhibitory properties, but the aza substrate analogue 12a showed reversible inhibition vs. DAP-AT and time dependent inhibition in the absence of the natural substrate 4. Substrate analogue 12a is thefirst example of an amide inhibitor of PLP dependent enzymes. Antibiotic properties of 12a were also briefly assessed.
- Cox,Wang
-
p. 2022 - 2034
(2007/10/03)
-
- A flexible synthesis of azasugars and homoazasugars via olefin metathesis
-
A flexible synthesis of azasugars and homoazasugars from vinyl glycine methyl ester is described. The syntheses, which are based on ring closing olefin metathesis steps and stereocontrolled functionalizations of the formed double bonds, offer a broad vari
- Huwe, Christoph M.,Blechert, Siegfried
-
-
- A novel approach to azasugars from vinyl glycine methyl ester via olefin metathesis
-
A novel strategy for the synthesis of azasugars from vinyl glycine methyl ester was designed, using an olefin metathesis as a key step. As a first test of this strategy, rac-trans-2-hydroxymethyl-3-hydroxypyrrolidine, which was isolated as the (2R,3S)-iso
- Huwe, Christoph M.,Blechert, Siegfried
-
p. 1621 - 1624
(2007/10/02)
-
- Structure and Stereochemistry of Three Phytotoxins, Syringomycin, Syringotoxin and Syringostatin, Produced by Pseudomonas syringae pv. syringae
-
The structures of two phytotoxins, syringomycin and syringotoxin, produced by Pseudomonas syringae pv. syringae, were determined.Several amino acid residues of syringomycin were different from those in the syringostatins.Syringotoxin B proved to be syringostatin A.The three kinds of phytotoxins showed close structural similarity, and the stereochemistry of their components was deduced and compared.
- Fukuchi, Naoyuka,Isogai, Akira,Nakayama, Jiro,Takayama, Seiji,Yamashita, Shuichi,et al.
-
p. 1149 - 1158
(2007/10/02)
-
- SYNTHESIS OF α-AMINO ACIDS WITH β,γ-UNSATURATED SIDE CHAINS
-
α-Amino acids with allenyl, vinyl and acetylenic side chains can be synthesized using non-enolate based strategies.The ester enolate-Claisen rearrangement applied to propargylic esters of N-protected α-amino acids is of limited utility since only poor yields of allenic product are obtained with the N-Boc glycine esters, the system which give the most reproducible results.However, α-allenyl-α-amino acids that are fully functionalized on the α-carbon are available through the agency of 4-allenyl-2-phenyloxazolones 4 ( obtained from propargyl esters of N-benzoyl protected amino acids via cyclization and Claisen rearrangement ) provided that Meerwein's reagent is used to facilitate hydrolysis of the benzamide function in 5.A variety of α-substituted glycinates, including those with α-vinyl and α-acetylenic functions, can be prepared using a two step sequence involving condensation of the cationic glycine synthon 22 with various organomagnesium reagents, followed by hydrolysis.
- Castelhano, Arlindo L.,Horne, Stephen,Taylor, Gregg J.,Billedeau, Roland,Krantz, Allen
-
p. 5451 - 5466
(2007/10/02)
-
- REACTIONS OF AN ELECTROPHILIC GLYCINE CATION EQUIVALENT WITH GRIGNARD REAGENTS A SIMPLE SYNTHESIS OF β,γ-UNSATURATED AMINO ACIDS
-
A simple and general synthesis of α-amino acids employing vinyl and alkyl Grignard reagents with a glycine cation equivalent is described.
- Castelhano, Arlindo L.,Horne, Stephen,Billedeau, Roland,Krantz, Allen
-
p. 2435 - 2438
(2007/10/02)
-
- Allylic Selenides in Organic Synthesis: New Methods for the Synthesis of Allylic Amines
-
Oxidative rearrangement of allylic selenides in the presence of various amine nucleophiles provides synthetic access to a variety of allylic amine derivatives.The stereochemical outcome of these reactions has been investigated, and is consistent with a -sigmatropic rearrangement mechanism.Several D-α-amino acids and racemic β,γ-unsaturated α-amino acids were prepared in this manner.A variant of this process employing an achiral allylic selenide and chiral amide afforded protected allylic amines in low diastereoisomeric excess.
- Shea, Regan G.,Fitzner, Jeffrey N.,Fankhauser, John E.,Spaltenstein, Andreas,Carpino, Philip A.,et al.
-
p. 5243 - 5252
(2007/10/02)
-
- Synthesis of Protected Racemic β,γ-Unsaturated-α-Amino Acids via γ-Phenylseleno-α,β-Unsaturated Esters
-
Oxidative rearrangement of γ-phenylseleno-α,β-unsaturated esters (1) with the N-chlorosuccinimide/N,N-diisopropylethylamine/alkyl carbamate reagent combination affords preparatively useful yields of protected β,γ-unsaturated-α-amino acids (2).
- Fitzner, Jeffrey N.,Pratt, Daniel V.,Hopkins, Paul B.
-
p. 1959 - 1962
(2007/10/02)
-