Cyanohydrin reaction
A
Cyanohydrin reaction is an
organic reaction by an
aldehyde or
ketone with a
cyanide anion or a
nitrile to form a
cyanohydrin. This
nucleophilic addition is a
reversible reaction but with
aliphatic carbonyl compounds equilibrium is in favor of the reaction products. The cyanide source can be potassium cyanide,
sodium cyanide or
trimethylsilylcyanide. With aromatic aldehydes such as
benzaldehyde the
benzoin condensation is a competing reaction. The reaction is used in
carbohydrate chemistry as a chain extension method for example that of D-
xylose.
Reaction of acetone with sodium cyanide to hydroxyacetonitrile |
Reaction of benzoquinone with trimethylsilylcyanide, catalyst KCN is introduced as a 1:1 complex with the Crown ether 18-crown-6 |
Reaction of benzoquinone with trimethylsilylcyanide in tetrachloromethane, catalyst KCN is introduced as a 1:1 complex with the Crown ether 18-crown-6chain extension of D-xylose in equilibrium with its hemiacetal with KCN to the cyclic esterThe
asymmetric cyanohydrin reaction of
benzaldehyde with trimethylsilylcyanide is made possible by employment of (R)-
Binol 1 at 1 to 10%
catalyst loading. This
ligand firsts reacts with a lithium alcoxy compound to form a lithium binaphtholate Complex.
 |
Asymmetric reaction of benzaldehyde with (R)-Binol-lithium(i-propyloxy) gives (S)-cyanohydrin with 98% ee |
Asymmetric reaction of benzaldehyde with (R)-Binol-lithium(i-propyloxy) gives (S)-cyanohydrin with 98% ee * Cyanohydrin reaction of
formaldehyde to hydroxyacetonitrile or glycolonitrile with sodium cyanide in
Organic Syntheses Coll. Vol. 2, p.387; Vol. 13, p.56
Article* Cyanohydrin reaction of
formaldehyde with potassium cyanide
Organic Syntheses Coll. Vol. 3, p.436; Vol. 27, p.41
Article* Cyanohydrin reaction of
acetophenone with potassium cyanide
Organic Syntheses Coll. Vol. 4, p.58; Vol. 33, p.7
Article* Cyanohydrin reaction of D-
xylose with potassium cyanide
Organic Syntheses Coll. Vol. 4, p.506; Vol. 36, p.38
Article* Cyanohydrin reaction of
acetone with potassium cyanide
Organic Syntheses Coll. Vol. 2, p.7; Vol. 15, p.1
Article* Cyanohydrin reaction of
benzoquinone with trimethylsilylcyanide
Organic Syntheses Coll. Vol. 7, p.517; Vol. 60, p.126
Article*
1 Chiral Lithium Binaphtholate Aqua Complex as a Highly Effective Asymmetric Catalyst for Cyanohydrin Synthesis Manabu Hatano, Takumi Ikeno, Takashi Miyamoto, and Kazuaki Ishihara
J. Am. Chem. Soc.;
2005; 127(31) pp 10776 - 10777
AbstractSupport info plus proposed transition state
