Selective 4,6-O-benzylidene formation of methyl α-D-mannopyranoside using 2,6-dimethylbenzaldehyde.
While methyl α-d-glucopyranosides and α-d-galactopyranosides selectively form 4,6-O-benzylidenes when reacted with excess benzaldehyde in the presence of acid catalyst methyl α-d-mannopyranosides does not exhibit the same selectivity because of the cis-arrangement of the C2 and C3 hydroxyl groups. The selectivity for the 4,6-O-benzylidene is restored by using 2,6-dimethylbenzaldehyde instead of benzaldehyde. In addition the excess 2,6-dimethylbenzaldehyde is easily recovered from the reaction by extraction with petroleum ether and can be reused without further purification. The 2,6-dimethylbenzylidene exhibits properties similar to the unsubstituted benzylidene with regard to chemical synthesis.
Stonehill College, 320 Washington Street, Easton, MA 02357, United States. Electronic address: lliotta@stonehill.edu.
Louis J
LJ
Liotta
Stonehill College, 320 Washington Street, Easton, MA 02357, United States.
Jennifer F
JF
Chalmers
Stonehill College, 320 Washington Street, Easton, MA 02357, United States.
Jessica N
JN
Falco Marshall
Stonehill College, 320 Washington Street, Easton, MA 02357, United States.
Timothy E
TE
Ferreira
Stonehill College, 320 Washington Street, Easton, MA 02357, United States.
Hannah E
HE
Mullen
Stonehill College, 320 Washington Street, Easton, MA 02357, United States.
Nicholas J
NJ
Pace
D001547:Benzaldehydes / Q000737:chemistry*; D001597:Benzylidene Compounds / Q000737:chemistry*; D008766:Methylmannosides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure
D001547:Benzaldehydes; D001597:Benzylidene Compounds; D008766:Methylmannosides; C008466:methylmannoside
2,6-Dimethylbenzylidene; 4,6-O-Benzylidene-α,d-mannopyranoside; Methyl α-d-mannopyranoside, protected; Protective group; Regioselective