A novel, chemoselective one-pot procedure for the preparation of 3H-spiro[isobenzofuran-1,2′-pyrrole]-3,3′(1′H)-dione derivatives via oxidative cleavage of 3a,8b-dihydroxyindeno[1,2-b]pyrroles

Facile Chemoselective synthesis of 2‐(2‐(Methoxycarbonyl)‐3‐oxo‐2,3‐dihydrobenzofuran‐2‐yl)benzoic acids and 3H,3’H‐Spiro[benzofuran‐2,1′‐isobenzofuran]‐3,3′‐dione derivatives

“…Based on the well‐known chemistry of the oxidation of vicinal diols by lead(IV) acetate, and according to our related experiences, a reasonable mechanism is proposed in Scheme . The oxidation of vicinal diol 7 via intermediate A gives the 6 H –dibenzo[ b , f ]oxocine‐6,11,12‐trione derivative B which, due to suitable oriented electron‐donor oxygen (O‐5) and electron‐withdrawing carbonyl group (C‐11) of oxocin ring, is prone to hydrolysis to form 2‐(2‐hydroxy‐3‐oxo‐2,3‐dihydrobenzofuran‐2‐yl)benzoic acids C .…”

“…In the continuation of our recent research programs on the development of novel methods for the synthesis of benzofuran and isobenzofuran derivatives, we decided to investigate the oxidation of 4b,9b–dihydroxy‐7‐methyl‐4b,9b–dihydro‐10 H ‐indeno[1,2‐ b ]benzofuran‐10‐one 7a as the model compound using lead(IV) acetate in acetic acid (Scheme ).…”

One-Pot Synthesis of Spiro-isobenzofuran Compounds via the Sequential Condensation/Oxidation Reaction of Ninhydrin with 4-Amino-1,2-naphthoquinones/2-Amino-1,4-naphthoquinones under Mild Conditions

“…Accordingly, 3 H ,3′ H -spiro­[benzofuran-2,1-isobenzofuran]-3,3-diones and 5-methyl-3,3′-dioxo-3 H ,3′ H -spiro­[furan-2,1′-isobenzofuran]-3,3′-dione derivatives were efficiently synthesized under mild and green reaction conditions. In this line of research and in continuation of our efforts to develop new methods for the synthesis of organic compounds via oxidative cleavage of in situ generated cyclic vicinal diols, − herein, we report the results of our investigations on the synthesis of various new spiro-isobenzofuran compounds starting from ninhydrin and 4-amino-1,2-naphthoquinones/2-amino-1,4-naphthoquinones (Scheme , eq 3).…”

Ninhydrin Adducts as Valid Synthon in Organic Synthesis: A Review

“…In 2014, Mohammadizadeh et al designed a chemoselective procedure for the synthesis of spiro‐isobenzofurano pyrrole scaffold 23 involving ninhydrin‐enamine adducts, namely, 3a,8b‐dihydroxyindeno[1,2‐ b ]pyrroles 22 derived from ninhydrin 1 andenamine 21 . They employed oxidative cleavage strategy using H 5 IO 6 at room temperature for the exclusive formation of spiro product 23 .…”