Synthesis of spiro[2H-indole-2,1′-1H-isoindole]-3,3′-diones, spiro[1H-isobenzofuran-1,2′-2H-indole]-3,3′-diones and spiro[benzofuran-2,1′-isobenzofuran]-3,3′-diones via transannular reactions of eight membered ring intermediates

✍ Scribed by James L. Bullington; John H. Dodd

• Publisher: Journal of Heterocyclic Chemistry
• Year: 1998
• Tongue: English
• Weight: 519 KB
• Volume: 35
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570350223

✦ Synopsis

Abstract

An auto oxidation‐rearrangement product 4 was isolated from a high dilution reaction of ninhydrin with 3,4,5‐trimethoxyaniline in water. A general synthesis of this compound and its derivatives 4–6 was devised by oxidation of tetrahydroindeno[1,2‐b]indol‐10‐ones 1–3 with sodium periodate to give isoindolo[2,1‐a]‐indole‐6,11‐diones 4–6 in good yield. Compounds 4–6 can be easily transformed into spiro[1__H__‐isobenzofuran‐1,2′‐2__H__‐indole]‐3,3′‐diones 8–10, spiro[2__H__‐indole‐2,1′‐1__H__‐isoindole]‐3,3′‐diones 11–13 and isoindole[1,2‐a:2′,1′‐b]pyrimidine‐5,15‐diones 15, 16 in high yields. Analogous reactions were performed on 3‐amino‐5a, 10a‐dihydroxybenzo[b]indeno[2,1‐d]furan‐10‐one (17) to give a dibenzoxocintrione 18, spiro‐[benzofuran‐2,1′‐isobenzofuran]‐3,3′‐dione 19 and an isoindol‐1‐one 20.