- A photochemical approach to phenylalanines and related compounds by alkylation of glycine
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Phenylalanines can be prepared on UV photolysis of protected glycines in the presence of di-tert-butyl peroxide, substituted toluenes and the photosensitiser benzophenone. These reactions, which lead to highly selective mono-alkylation at the α-position of glycines, involve coupling of captodative α-glycine radicals with benzyl radicals. This method can be used to selectively alkylate a variety of glycine derivatives using a range of substituted toluenes under neutral reaction conditions.
- Knowles, Haydn S.,Hunt, Keith,Parsons, Andrew F.
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p. 8115 - 8124
(2007/10/03)
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- Photochemical alkylation of glycine leading to phenylalanines
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UV photolysis of protected glycines in the presence of di-tert-butyl peroxide, benzophenone and substituted toluenes is shown to lead to selective alkylation at the α-position. Phenylalanines are isolated in yields of generally > 50% (based on recovered s
- Knowles,Hunt,Parsons
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p. 7121 - 7124
(2007/10/03)
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- Pyrazine Chemistry. III. Synthesis and Stereochemistry of 1,4-Dimethyl and 1,4-Diacetyl Derivatives of 3,6-Dibenzylpiperazine-2,5-dione
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The trans- and (+/-)cis-isomers of 1,4-dimethyl-and 1,4-diacetyl-3,6-dibenzylpiperazine-2,5-dione were synthesized.The hydriodic acid reduction of 3,6-dibenzylidene-1,4-dimethylpiperazine-2,5-dione gave (+/-)-cis-3,6-dibenzyl-1,4-dimethylpiperazine-2,5-dione although this product has previously been assigned the trans-geometry.The unknown isolated from the permanganate oxidation of (+)-cis-1,4-diacetyl-3,6-dibenzylpiperazine-2,5-dione has been identified as the corresponding trans-isomer.
- Marcuccio, Sebastian M.,Elix, John A.
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p. 2397 - 2402
(2007/10/02)
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