Synthese des 4‐Dimethylallyl‐tryptophans sowie der Tryptophan‐essigsäure‐(4)

Abstract

4-Dimethylallyl-tryptophanDie Ergot-und Clavin-Alkaloide werden von Claviceps-Pilzen aus Tryptophan einerseits und Mevalonsaure andererseits gebildet, wobei letztere wahrscheinlich uber Isopentenylpyrophosphat und Dimethylallylpyrophosphat eingebaut wird 1). Fiir die weiteren Umwandlungen dieser Reaktionskomponenten lassen sich zwei ziemlich verschiedene Reaktionswege diskutieren, die im einzelnen besprochen werden sollen, wenn uber den Einbau radioaktiv markierter Zwischenprodukte berichtet wird. Bei dem einen Weg wird 4-Dimethylallyl-tryptophan durchlaufen, eine Verbindung, deren Synthese im folgenden beschrieben wird.

Ergot alkaloids. Ergolines and related compounds as inhibitors of prolactin release

“…The CHClg layer was washed with dilute NaHCOg solution and then with H20, dried over anhydrous Na2S04, filtered, and evaporated under vacuum to a syrup which on crystallization from MeOH gave 4 mg of 13, mp 229-230°. The reported melting point is 226-229°.38 An additional 5 mg of crude alcohol was obtained on evaporation of the mother liquor from the recrystallization: mass spectrum (low resolution) m/e (rel intensity) 257 (20), 256 (M+, 100), 255 (6.4), 197 (14), 167 (20), 154 (33), 144 (37), 137 (14); mass spectrum (high resolution) caled for CigHgoNgO, 256.1574; found, 256.1570. Elymoclavine .…”

“…Chromatography of the residue on a column of silica gel (20 g, activity 2-3, 70-325 mesh, EM Reagent) with Me^O-EtOAc-DMF (5:5:1) gave 50 mg of elymoclavine. Further elution gave 50 mg of product (53% based on recovered elymoclavine) after recrystallization of the residue from CHCls-petroleum ether, mp 107-115°, which was homogeneous on tic (AED system): ir (KBr) 3.0 (NH, NH2), 5.9 µ (CONH2); nmr (CDC13) 2.50 (s, NCH3), 4.6 (s, CH2O), 8.0 (s, NH); uv (MeOH) max (e) 293 (6640), 284 (8300), 222 (29,000); mass spectrum (low resolution) m/e (rel intensity) 298 (4), 297 (M+, 20), 253 (20), 235 (30), 234 (100), 233 (37), 167 (31), 155 (34); mass spectrum (high resolution) caled for CrrHis^Ch, 297.1477; found, 297.1468. Anal.…”

“…The tricyclic clavines (Table II) were obtained by treatment of agroclavine methiodide (42) and elymoclavine methiodide (43) with silver oxide followed by Emde-Birch reduction to give Nmethy ldeoxychanoclavine I (19) and N-methylchanoclavine I (20), respectively.22 Demethylation of 20 with diethyl azodicarboxylate as described by Fehr23 was used to prepare chanoclavine I (21).…”

Conversion of agroclavine to setoclavine and isosetoclavine in cell‐free extracts from Claviceps sp. SD 58 and in a thioglycolate‐iron. (II) system

“…Setoclavine and isosetoclavine were also separated from the alkaloid extract by preparative TLC as described for the incubated systems. (7)(8)(9). The decarboxylation of 4-bromoindole-2-carboxylic acid was carried out as described by Kohler and Anderson (10).…”

A Short Synthesis of Optically Active γ,γ-Dimethylallyltryptophan (DMAT)

“…DMAT 1 is not only important in the biosynthetic pathway but also attractive as a potential synthetic intermediate for ergot alkaloids. The first total synthesis of DL-1 was reported 4 in 1963 by Plieninger's group starting from 4-formylindole. This synthesis has played an important role in the supply of DL-1 for biosynthetic research until Nettekoven's group 5 developed the synthesis of optically active DMAT (S)-1 by enzymatic kinetic resolution of the phenacyl amide of DL-1 in 1995.…”