Enzymatic Control over Self- and Cross-Aldol Reactions

Significance The enzyme-catalyzed self- and cross-aldol additions of glycolaldehyde (GA) are reported. The investigated enzyme d -fructose-6-phosphate aldolase (FSA) proved to be very effective and able to differentiate carbonyl compounds in its donor and acceptor capabilities. Glycolaldehyde showed the highest donor properties, as i­llustrated in kinetic studies by its low Michaelis-Menten constant. The K M of glycolaldehyde was even lower than those for dihydroxyacetone and hydroxyacetone, respectively, both known to be well tolerated as donors by the FSA enzyme. Remarkably, even consecutive aldol additions were possible.