close

Вход

Забыли?

вход по аккаунту

?

код для вставки
2005
Cycloaddition reactions
O 0070
New Preparative Route to Hetaryldienes and Azadienes. — Tetrazolylacrolein (I)
as starting compound for the synthesis of novel trans-trans-dienes. The new
09- 028 serves
dienes (III), (IV), (V), (VI), and (XII) contain electron—withdrawing substituents as a
common feature. In contrast to their expected participance in [4 + 2] cycloadditions of
inverse electron demand, no cycloaddition of electron donating dienophiles is experienced. However, ester and acetyl bearing trans-trans-dienes react with the strongly
electron-withdrawn dienophile (VII) to give regular cycloadducts like (VIII).
Diels—Alder reaction of (III) with N-methylmaleinimide (IX) is only possible in ionic
liquid to furnish (X). Nitrones (XII) undergo 1,3-dipolar cyclizations with in-situ generated benzyne to furnish the fused isoxazolines (XIV). — (NAGY, I.; HAJOS*, G.;
RIEDL, Z.; Heterocycles 63 (2004) 10, 2287-2307; Chem. Res. Cent., Hung. Acad.
Sci., H-1525 Budapest, Hung.; Eng.) — H. Hoennerscheid
2005
Документ
Категория
Без категории
Просмотров
0
Размер файла
31 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа