Efficient synthesis of some oxalacetic acid and pyruvic acid derivatives from the reactions of 2,3-furandiones with 2-phenylindole

An Entry into Obtaining Pyrazole‐, Chromone‐, or Oxadiazole‐Substituted 1H‐Pyrazoles via 2,3‐Furandiones

“…So far, we have developed new routes in heterocyclic synthesis [20–22], and herein, we report our experimental results and present the plausible reaction mechanisms involved in the ring‐opening/recyclizations. These reactions consist of 1‐(pyrazole‐3‐yl)‐3‐(2‐hydroxy‐4‐methyl‐phenyl)‐1,3‐propandione (6), 1H‐pyrazole‐3‐chromone (7), 1H‐pyrazole‐3‐(3 or 4‐acetyl‐phenyl‐carboxylate) (10, 11), 1H‐pyrazole‐3‐carboxyhydrazide (13), 2,5‐pyrazole‐3yl‐oxadiazole (14), and bis‐1H‐pyrazole (15) (Fig.…”

A Golden Synthetic Approach to 2-(1H-Pyrrol-1-yl)anilines and Pyrrolo[1,2-a]quinoxalines through a Gold Carbene Intermediate

“…14a b When the NMR data for the resulting ynone derivatives with a 1,3-β-keto ester structure were analyzed, it was discovered that tautomerization occurred in a ratio of 1:1 for 1a and 1b and 1:3 for 1e – g , in agreement with the literature. 14c d However, the NMR spectra of ynone derivatives with only one carbonyl group and symmetric 1,3-diketo structures revealed no tautomerization.…”

Synthesis of Pyrrolizinone and Pyrrolizino[1,2-a]pyrrolizin-5-one Skeletons Starting From Pyrrole through a Single-Step and Catalyst-Free Approach

“…9 On the other hand, we have previously reported the reaction between a 2-phenylindole and a furandione 4 to give a series of C-3 substituted indole derivatives (Scheme 2 ). 10` b c Furandiones 4 have an attractive chemistry and can behave as Michael addition donors. 10d–g Consequently, some of those reactions prompted us to investigate the reaction of pyrrole with furandiones (Scheme 1 E).…”

“…We first investigated the reaction of 1 H -pyrrole ( 5 ) with the furandione 4a under various conditions. Whereas indoles attack furandiones 4 through their C-5 position to give indolebutyric acid derivatives (Scheme 2 ; the square indicates the attacked carbon), 10` b c pyrrole did not react with furandione 4a in the same way, but instead give the pyrrolizinone 6a ; we therefore attempted to optimize the reaction of pyrrole ( 5 ) with furandione 4a to give the pyrrolizinone 6a (Table 1 ).…”