The synthesis of a cyclopropane amino acid, trans-α-(carboxycyclopropyl)glycine, found in ackee seed

Cyclophilic Reactions of Allene‐1,3‐dicarboxylic Esters. Part 4. Pyrazolone Formation and a Novel Indole Synthesis from the Nucleophilic Addition of 1,2‐Diphenylhydrazine to Dimethyl Allene‐1,3‐dicarboxylate

“…While the pyrazolones (4) and (8) are formed by 5-exo-trig cyclisations of the enehydrazines (3) and (7) with the elimination of methanol as previously observed [5] , indole formation occurs by a rearrangement similar to that postulated for the Fischer indole synthesis (Scheme 3). This mechanism leads to the required products (5) and (9).…”

“…path a will lead to the indoles (5) and (9) whereas lactam formation occurs by path b (Scheme 3). In the case of the reaction with 1,2-diphenylhydrazine and dimethyl penta-2,3-dienedioate, indole cyclisation occurs in preference to lactam formation and thus the S-exo-trig reaction is favoured to the exclusion of the 7-exo-trig alternative [7]. The postulate that indole formation occurs by the key step in the Fischer indole synthesis led to a study of factors which control pyrazolone or indole formation since it is well known that the rearrangement process of the enehydrazine is catalysed [8] by proton and Lewis acids.…”

A Rhodium‐Catalyzed Route for Oxidative Coupling and Cyclization of 2‐Aminobenzyl Alcohol with Ketones Leading to Quinolines.

“…This compound was obtained as a pale yellow oil, (lit [15] 105-108°/1.0 mmHg); 1 18,19.35,28.92,43.58,118.55,124.56,125.93,126.40,127.97,128.15,135.22,146.76,165.99. 1,2,3,.…”

Efficient Stereoselective Syntheses of Constrained Glutamates via Michael‐Induced Ring Closing Reactions

“…Besides approaches to introduce the amino acid functionality via Strecker reac-tion, [8] several routes have been developed to construct the ring units.…”