title: 2-silyloxy-1,2-oxazines, a new type of acetals of conjugated nitroso alkenes.
abstract: 3-alkyl-substituted 1,2-oxazine N-oxides 2 can be selectively transformed into 2-silyloxy-1,2-oxazines 1 upon treatment with silylating reagents. In the solid state derivatives 1 adopt a chair conformation with the pyramidal nitrogen atom, whereas in solution they exist as an equilibrating mixture of two conformers (DeltaG++ 55-60 kJ/mol). A preliminary study of the reactivity of nitrosals 1 has shown that they react with O- and N-stabilized carbocations to yield 1,2-oxazine N-oxides with a functionalized alkyl substituent at the 3-position. Moreover, compounds 1 can rearrange into silyloxy-1,2-oxazines 5 and react with morpholine to produce 3-morpholinoalkyl-1,2-oxazines 7 existing in a tautameric equilibrium with open-chain oximes 6.
authors: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Leninsky Prosp. 47, Moscow, Russian Federation.
authors: Alexander A
authors: AA
authors: Tishkov
authors: Alexey V
authors: AV
authors: Lesiv
authors: Yulya A
authors: YA
authors: Khomutova
authors: Yury A
authors: YA
authors: Strelenko
authors: Ivan D
authors: ID
authors: Nesterov
authors: Michael Yu
authors: MY
authors: Antipin
authors: Sema L
authors: SL
authors: Ioffe
authors: Scott E
authors: SE
authors: Denmark