2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate synthase (, ADH synthase, ADHS, MJ0400 (gene)) is an enzyme with systematic name L-aspartate 4-semialdehyde:1-deoxy-D-threo-hexo-2,5-diulose 6-phosphate methylglyoxaltransferase. This enzyme catalyses the following chemical reaction
The enzyme plays a key role in an alternative pathway of the biosynthesis of 3-dehydroquinate.