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

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172 NITRONES: NOVEL STRATEGIES IN SYNTHESIS<br />

O<br />

O<br />

O<br />

OH<br />

NH2OH<br />

74 %<br />

140 141 E, Z<br />

H<br />

C N<br />

Ar OH<br />

144 Ar- =<br />

145 Ar- = O N<br />

+ −<br />

Na<br />

EtOH<br />

O<br />

O<br />

N OH<br />

Scheme 2.51<br />

H<br />

OH<br />

C N<br />

Ar ONa<br />

H<br />

146 R = -CO 2Et<br />

147 R = -CH3<br />

Acetone<br />

2,2,-DMP<br />

TsOH<br />

R<br />

EtOH Br CO2Et CH3 C N<br />

−<br />

Ar O<br />

Scheme 2.52<br />

R<br />

+<br />

CO 2Et<br />

CH3<br />

O<br />

O<br />

DEEPN: R = CO2Et, Ar =<br />

EPPyON: R = CH 3, Ar =<br />

−<br />

O<br />

142<br />

O<br />

143<br />

O +<br />

N<br />

(30%)<br />

+<br />

N<br />

O N<br />

+ −<br />

O<br />

(35%)<br />

Interaction of Mannich base methyliodides (148, R= Ph, 2-Thenyl) with antibenzaldoxime<br />

gives d<strong>in</strong>itrones (149) (Scheme 2.53) (307).<br />

Formation of heterocyclic nitrones (151) from the correspond<strong>in</strong>g am<strong>in</strong>o oximes<br />

(150) has been observed upon treatment with Hg(II)-ethylenediam<strong>in</strong>etetraacetic<br />

acid (EDTA) (Scheme 2.54) (308, 309).<br />

O<br />

O

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