Manganese(III)-mediated intermolecular cyclization reactions of alkenes and active methylene compounds

✍ Scribed by Jie Ouyang; Hiroshi Nishino; Kazu Kurosawa

• Publisher: Journal of Heterocyclic Chemistry
• Year: 1997
• Tongue: English
• Weight: 402 KB
• Volume: 34
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570340114

✦ Synopsis

Abstract

The reactions of 1,1‐diphenylethene, 1,1‐bis(4‐chlorophenyl)ethene, 1,1‐bis(4‐methylphenyl)ethene, and 1,1‐bis(4‐methoxyphenyl)ethene with 3,5‐diacetyl‐2,6‐heptanedione in the presence of manganese(III) acetate in acetic acid at 80° yielded 4,6‐diacetyl‐8,8‐diaryl‐1,3‐dimethyl‐2,9‐dioxabicyclo[4.3.0]non‐3‐enes (41‐48%), 5‐acetyl‐2,2‐diaryl‐6‐methyl‐2,3‐dihydrobenzo[b]furans (20–21%), 3‐acetyl‐5,5‐diaryl‐2‐methyl‐4,5‐dihydrofurans (5–10%), and benzophenones (3–7%). Similarly, the reactions of 1,1‐diarylethenes with dimethyl 2,4‐diacetyl‐1,5‐pentanedioate or diethyl 2,4‐diacetyl‐1,5‐pentanedioate gave the corresponding 4,6‐bis(alkoxycarbonyl)‐8,8‐diaryl‐1,3‐dimethyl‐2,9‐dioxabicyclo[4.3.0]non‐3‐enes in moderate yields.