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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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448 NITRONATES<br />

MeO2CCH2NO2 11<br />

RCHO<br />

[MeO2CC(NO2) CHR]<br />

MeO2CCH 2NO 2<br />

[MeO 2CCH(NO 2)] 2CHR′<br />

+ − base<br />

[Me2XCH2R]Br<br />

[MeO 2CCH(NO 2)] Met<br />

−HBr<br />

X = S, Se;<br />

R = H, COAr<br />

R1 è R2 – H, alkyl, aryl<br />

R3 – alkyl, aryl<br />

+<br />

[Me2NS(O) CH<br />

Ph<br />

14<br />

base<br />

Me 2X<br />

−<br />

12<br />

+<br />

CR 1 R 2 ] BF4 −<br />

MeO 2C<br />

O<br />

RCH 2I<br />

O<br />

−MetI MeO2CCH N<br />

A<br />

OCH2R R CO2Me<br />

5<br />

Scheme 3.15<br />

+ −<br />

R<br />

O N<br />

O<br />

R 1<br />

R 2<br />

R = H, alkyl; R 1 <strong>and</strong> R 2 - alkyl, aryl<br />

R 1 R 2<br />

R 1<br />

R 2<br />

13<br />

R<br />

NO2 O N<br />

or<br />

5<br />

Me2XCHR<br />

R<br />

O<br />

R 1<br />

base<br />

R 3<br />

NO2<br />

R 2<br />

R 3<br />

N<br />

−Me 2X<br />

RCHO + MeO 2CCH NOH<br />

35% – 45%<br />

O<br />

R – aryl, tert. alkyl<br />

O<br />

R 2<br />

R<br />

R 2<br />

R 1<br />

R 1<br />

R<br />

R 3<br />

N<br />

O<br />

5<br />

R 3<br />

O<br />

NO2<br />

13<br />

RCH 2NO2 Me 2NSCH 2CR 1 R 2 CHRNO 2<br />

−Me 2NSPh<br />

O<br />

Scheme 3.16<br />

Ph<br />

O<br />

−HBF 4<br />

Me2NS CH2 CR 1 R 2<br />

Ph<br />

A<br />

+<br />

−<br />

B<br />

O<br />

CR<br />

N<br />

O<br />

(1)<br />

BF 4 −<br />

(2)

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