Categories: C-C Bond Formation > Oxygen-containing molecules > Carboxyl derivatives >
Synthesis of α-hydroxy carboxylic acids, esters and amides
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Recent Literature
In the presence of CsF, a wide range of α-substituted α-siloxy silanes were
carboxylated under 1 atm of CO2 via Brook rearrangement. Various
α-substituents including aryl, alkenyl, and alkyl groups were tolerated to
afford α-hydroxy acids in good yields. A one-pot synthesis from aldehydes using
PhMe2SiLi and CO2 provides α-hydroxy acids without the
need for isolation of the α-hydroxy silane.
T. Mita, Y. Higuchi, Y. Sato, Org. Lett., 2014,
16, 14-17.
Use of a masked acyl cyanide (MAC) reagent bearing a tert-butyldimethylsilyl
group allows the synthesis of α-siloxy esters via a one-pot reaction with
various aldehydes and alcohols.
H. Nemoto, R. Ma, T. Kawamura, K. Yatsuzuka, M. Kamiya, M. Shibuya, Synthesis, 2008,
3819-3827.
α-Acetoxy esters or amides were synthesized directly and in one portion from
aldehydes and alcohols or amines by one-carbon homologation using a masked acyl
cyanide reagent bearing an acetyl group.
H. Nemoto, T. Kawamura, K. Kitasaki, K. Yatsuzuka, M. Kamiya, Y. Yoshioka, Synthesis, 2009,
1694-1702.
A one-pot method allows the synthesis of α-siloxy-Weinreb amides from aldehydes
using N,O-dimethylhydroxylamine and a masked acyl cyanide reagent bearing
a tert-butyldimethylsilyl group. The TBS group avoids the competitive
reaction toward N-methoxy-N-methyl-2-amino-1-siloxymalononitrile.
H. Nemoto, R. Ma, H. Moriguchi, T. Kawamura, M. Kamiya, M. Shibuya, J. Org. Chem., 2007,
72, 9850-9853.