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Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis : Novel ...

Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis : Novel ...

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542 NITRONATES<br />

R 2 = H<br />

R 1 = Me<br />

R 3 = N<br />

R<br />

R 2<br />

H<br />

R 2<br />

O<br />

NO2<br />

R 2<br />

N<br />

R3 O O<br />

Si<br />

O<br />

R3 NO2 R1 O N R<br />

O<br />

1<br />

R3 N R<br />

O O<br />

1<br />

R3 + + +<br />

− −<br />

N<br />

H<br />

Me<br />

R 1<br />

155 a,b<br />

a = 40%; b = 72%<br />

a - R 1 = R 2 = H<br />

b -R 1 = Me; R 2 = H R 3 =<br />

R<br />

Me<br />

SiO 2<br />

R 2<br />

R 2<br />

153a,b 154a,b<br />

O N H<br />

O<br />

R<br />

N<br />

NO2 Me<br />

a: R = H<br />

b: R = CH2OMe 156a,b 157a,b<br />

+<br />

N<br />

H<br />

158a,b<br />

Scheme 3.123<br />

Me<br />

N<br />

NO2<br />

−<br />

O<br />

a = 72%<br />

b = 63% (de 71%)<br />

+<br />

− −<br />

R 1

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