A-Bromovaleric acid

Carboxylic acids, acyl chlorides, and sulfonyl chlorides used for deri-vatization of 4-aminophenylalanine and >-4-am i n op h e ny I a I a n i n e are as follows 5-hydantoinacetic acid, / ran, v - 4 - co t i n i n ec a r b o xy I i c acid, isonicotinic acid, 3-pyridinepropionic acid, 4-hydroxyphenylacetic acid, 2-butynoic acid, 2-pyrazinecarboxylic acid, cyclopropanecarboxylic acid, 3-hydroxy-2-qui-noxaline carboxylic acid, 5-bromovaleric acid, propargyl chloroformate, 3,4-dimethoxybenzoyl chloride, 2-thiophenesulfonyl chloride, 3-thiophene-carboxylic acid, 2-thiophenecarboxylic acid, 2-methylbutyric acid, 2-thio-pheneacetyl chloride, benzoic acid, furylacrylic acid, 4-nitrophenyl acetic acid, 2,5-dimethoxyphenylacetic acid, p-toluenesulfonyl chloride, 4-(di-methylamino)phenylacetic acid, 3-indolepropionic acid, phenoxyacetic acid, 3-(dimethylamino)benzoic acid, cyclohexanecarboxylic acid, naphtha-lenesulfonyl chloride, 4-bromophenylacetic acid, 4-bromobenzoic acid, 2-phenoxybutyric acid, 3,4-dichlorophenylacetic acid, (l-naphthoxy)acetic acid. 

Continuing their rational design, Jiracek and al. described a-aminophosphinic acids 239, 240, structurally close to compounds 235 and 237 [161]. Each structure was obtained in 56-64% yield, by mixing ethyl 5-bromovalerate or ethyl 5-bromo-3,3-dimethylpentanoate with phosphinomethionine 238 in the presence of sodium and ammonia (Scheme 46). The //-phosphinic acid intermediate 238 was readily accessible by a sequence of three steps from acrolein [162-164]. 

An Algox Pharmaceutical group reported a preparation of MNA capitalizing on a C5 + C5 strategy, and based on the alkylation of bromovaleric add (S2) with the lithium anion of 3-methyl-l-butyne (S3), followed by stereoselective reduction of 8-methyl-6-noninoic acid (S4) to ( )-MNA by dissolving-metal reduction. 

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