Garner���s aldehyde

Chiral amino aldehydes are remarkable as their aldehyde groups can be converted into a wide range of structural frameworks are the intermediates in several important industrial processes. However the characteristic reactivity of amine and aldehyde functionalities is a major task in case of preparation and synthetic efficacy of α-amino aldehydes as nitrogen protection assists undesired epimerization processes. Fischer’s discovery of glucosamine in 1902 in which unprotected amine and aldehyde functionalities are stabilized as a cyclic hemiacetal is the first example of unprotected α-amino aldehydes. Later on he also synthesized glycinal which was characterized through degradation studies due to its inherent instability via self-condensation. The probability for intramolecular stabilization of α-amino aldehydes is not significant but the presence of incompatible functional groups make these unstable and hence suitable N-and C-protection is vital.