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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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H + O<br />

N<br />

B− − − −<br />

H<br />

N<br />

− BH<br />

−<br />

O<br />

+<br />

N<br />

+<br />

+ O<br />

N<br />

R 1<br />

R 2<br />

O H N<br />

+<br />

N<br />

−O<br />

Scheme 2.123<br />

O<br />

LDA, −70°C<br />

NITRONE REACTIONS 233<br />

R2 R1 [0]<br />

A<br />

B<br />

− H2O<br />

−<br />

OH<br />

O + N<br />

+<br />

N O<br />

N<br />

N<br />

O +<br />

N<br />

−<br />

N<br />

+<br />

O<br />

R Yield % Yield %<br />

1 R2 R1 R2 H Ph 70 CH3 Ph 70<br />

H CH 3 55 CH3 2-Thienyl 50<br />

-(CH2) 5- 47 CH 3 2-Pyridyl 65<br />

-(CH2)4- 40 H 2-Pyrryl 55<br />

-(CH 2) 11- 46 Ph Ph 75<br />

CH3 CH2=CH- 65 CH3 Ferrocenyl 60<br />

CH3 CH 2=CH-CH 2-CH 2- 62 -CH 2-C(CH 3) 2-N-C(CH 3) 2- 65<br />

Ph<br />

H<br />

R 1<br />

H<br />

H<br />

N<br />

−O<br />

N<br />

Scheme 2.124<br />

R<br />

O<br />

N<br />

1<br />

R2 R1 R2 + + +<br />

225<br />

R 2<br />

Ph<br />

CH 3<br />

Yield %<br />

66<br />

58<br />

R 1<br />

H<br />

CH 3<br />

Scheme 2.125<br />

Ph<br />

OH<br />

−O<br />

R<br />

(CH3) 2C=CH-(CH2) 2-<br />

C(CH3)=CH- CH2=CH-CH2-CH2 2 Yield %<br />

67<br />

72<br />

N<br />

−<br />

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