A general preparation of β-substituted tryptophan esters

A Convenient Synthesis of Indole-Substituted 2-Pyrrolidones and Their Cyclized Derivatives

“…Decarboxylation of AЈ or BЈ would give 1 (Ar ϭ Indole) as a side product. Scheme 2 Synthesis of type A or B derivatives could be achieved using a protocol that was developed in our laboratory, [4] based on results reported by Yonemitsu. [5] It involved the trimolecular condensation between indole, Meldrum's acid, and aldehyde 6a؊c, in the presence of ,-proline as catalyst (Scheme 3), giving compounds 7a؊c in good yields (64Ϫ76%).…”

Reaction of 3‐(1‐Arylsulfonylalkyl)‐indoles with Easily Enolisable Derivatives Promoted by Potassium Fluoride on Basic Alumina

“…The resulting mono esters 15 undergo a Curtius rearrangement via acyl azide leading to tryptophan analogues 16 (Scheme 4). [19] Hydrolysis and de- 15…”

Enantioseparation of β-methyl-substituted amino acids with cyclodextrins by capillary zone electrophoresis☆

“…Racemic erythro-(2S,3S and 2R,3R)-␤-methylphenylalanine (erythro-␤-MePhe) (1a) and threo-(2S,3R and 2R,3S)-␤-methylphenylalanine (threo-␤-MePhe) (1b); erythro-(2S,3S and 2R,3R)-␤-methyltyrosine (erythro-␤-MeTyr) (2a) and threo-(2S,3R and 2R,3S)-␤-methyltyrosine (threo-␤-MeTyr) (2b); erythro-(2S,3S and 2R,3R)-␤-methyltryptophan (erythro-␤-MeTrp) (3a) and threo-(2S,3R and 2R,3S)-␤-methyltryptophan (threo-␤-MeTrp) (3b); erythro-(2S,3S and 2R,3R)-4-methyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (erythro-␤-MeTic) (4a) and threo-(2S,3R and 2R,3S)-4-methyl-1,2,3,4-tetrahy-droisoquinoline-3-carboxylic acid (threo-␤-MeTic) (4b) were prepared by literature methods [9,26] (Fig. 1).…”