Synthesis of 2-(3-Bromo-1,2,3,4-tetrahydro-1,4-epoxynaphthalen-2-yl)-2-hydroxy-5,5- dimethylcyclohexane-1,3-dione and Its Reaction with Silver Salts

Abstract

The addition of dimedone to oxabenzonorbornadiene was performed using Mn(III)acetate in the presence of HBr. The intermediate formed was trapped by bromine. The product was reacted with AgNO3 and AgClO4 in acetic acid. The expected dihydrofuran derivative was not formed. Instead, a hydroxylated dimedone compound on α-carbon was isolated. The structures of the compounds synthesized were characterized by 1H, 13C and 2D-NMR spectroscopy.

The addition of dimedone to oxabenzonorbornadiene was performed using Mn(III)acetate in the presence of HBr. The intermediate formed was trapped by bromine. The product was reacted with AgNO3 and AgClO4 in acetic acid. The expected dihydrofuran derivative was not formed. Instead, a hydroxylated dimedone compound on α-carbon was isolated. The structures of the compounds synthesized were characterized by 1H, 13C and 2D-NMR spectroscopy.

Keywords

• Mangan(III)acetate
• Dimedone
• Oxabenzonorbornadiene

Mangan(III)asetat Eşliğinde 2-(3-Bromo-1,2,3,4-tetrahidro-1,4-epoksinaftalen-2-il)-3-hidroksi-5,5-dimetilsiklohekze-2-enon’un Sentezi ve Gümüş Tuzları İle Reaksiyonu

Abstract

Mn(III)asetat eşliğinde dimedonun oksabenzonorbornadiene katılma reaksiyonundaki ara ürün HBr ile yakalandı. Katılma ürünü AgNO₃ ve AgClO₄ ile asetik asit içerisinde reaksiyona sokuldu. Beklenen dihidrofuran halkası oluşmadı. Bunun yerine dimedondaki α-karbonunun hidroksillendiği bileşik oluştu. Sentezlenen bileşiklerin yapıları ¹H, ¹³C ve 2D-NMR teknikleri ile karakterize edildi.Geçiş metallerinin tuzları yardımı ile oluşturulan karbon radikallerinin çift bağlara katılması, organik kimyada karbon-karbon bağının oluşturulmasında önemli yöntemlerden birisidir[1]. En yaygın kullanılanı ise Mn(III)asetat’tır. Heiba ve Dessau, Mn(III)asetat ile yapmış oldukları çalışmalarda gösterdiler ki asetik asit içerisinde alkenlere 1,3- dikarbonil bileşiklerinin katılmasıyla dihidrofuranlar oluşmaktadır[2] (Şekil 1). Oksidatif olarak elde edilen radikal 2 çift bağ karbonuna katılarak yeni radikal 3 oluşur. İlgili radikal (3) yükseltgenerek karbokatyon 4 oluşabilir ve halkalaşma sonrası proton kaybetmesiyle dihidrofuran oluşabilir (Rota A). Ya da radikal 3 önce halkalaşarak radikal 5’i ardından proton kaybetmesiyle dihidrofuran oluşturabilir (Rota B) [3,4].

Keywords

• Mangan(III)asetat
• Dimedon
• Oksabenzonorbornadien

References

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