1997 fused pyrimidine derivatives

fused pyrimidine derivativesR 0515

41 - 191Diene-Transmissive Hetero-Diels-Alder Reaction of Cross-ConjugatedAzatrienes: A Novel and Efficient Method for the Synthesis of Ring-Fused Nitrogen Heterocycles. — Azatrienes (I) react with (II) to givethe cycloadducts (III) without the regioisomer or the bis-adduct. A secondDiels-Alder cycloaddition of (III) with (IV) proceeds smoothly to yield thecycloadducts (V) with complete stereoselectivity. With (VI) and dimethylfumarate second cycloadditions are effected to produce cycloadducts withalmost no endo:exo-selectivity (cf. (VII), (VIII)). — (SAITO, T.; KIMURA,H.; CHONAN, T.; SODA, T.; KARAKASA, T.; Chem. Commun. (Cambridge)(1997) 11, 1013-1014; Dep. Chem., Fac. Sci., Sci. Univ. Tokyo, Shinjuku,Tokyo 162, Japan; EN)

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