D-Vinylglycine

Hallinan, K. O., Crout, D. H. G., Errington, W. Simple synthesis of L- and D-vinylglycine (2-aminobut-3-enoic acid) and related amino acids. J. Chem. Soc., Perkin Trans. 11994, 3537-3543. 

Since the piepataiion of I Chktto-D-vinylglycine ctaiiains some 20% of l>viiiy)glycine, p-vinylglycine ] CyA is made by the enzyme. 

The X-ray structure of [cp Ir(CNR)Cl2], CNR = l,3,4,6-tetra-0-acetyl-2-deoxy-2-isocyano-Q,, 3-D-glucosc, has been determined.428 The synthesis of chiral complexes of Ir111 with Q-amino acid anions, L-L, of general formula [cp Ir(Cl)(L-L )] (252), and their NMR spectroscopic characterization, have been detailed. The X-ray structures of (252), L-L = L-proline and [cp Ir(Cl)(L-His-OH)]Cl, His = histidine, are described.429 C-allylglycinate binds in a terdentate manner in (253), which has been characterized by X-ray diffraction studies.430 C-vinylglycinate forms complex (254). 

Schemes Model of mechanism-based inactivation of ACS by SAM (a-e) Model of mechanism-based inactivation of ACS by L-vinylglycine (l-VG) (f-g-d-e) Conversion of l-VG to a-ketobutyrate and ammonia catalyzed by ACS (f-h). Notations are as in Scheme 2. For details see text.

Intermolecular cyclopropanation reactions with ethyl diazoacetate have been employed for the construction of the cyclopropane-containing amino acid 7 (equation 25) Thus, rhodium(II) acetate catalysed decomposition of ethyl diazoacetate in the presence of d-cbz-vinylglycine methyl ester 5 afforded cyclopropyl ester 6 in 85% yield. Removal of the protecting group completed the synthesis of 7. Another example illustrating intermolecular cyclopropanation can be found in Piers and Moss synthesis of ( )-quadrone 8" (equation 26). Intermolecular cyclopropanation of enamide or vinyl ether functions using ethyl diazoacetate has also been used in the synthesis of eburnamonine 9", pentalenolactone E ester 10" and ( )-dicranenone A11" (equations 27-29). 

In order to achieve higher stereocontrol, the combination of a ribose-derived nitrone with modified vinylglycines is exploited to give products in a d.r. of greater than 95 586. 

Scheme 13.19 Identifying vinylglycine as possible precursor for polyoxamic acid 4.2 D-Erythro-Sphingosine...

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