Catalyzes a reversible aldol reaction between acetaldehyde and D-glyceraldehyde 3-phosphate to generate 2-deoxy-D-ribose 5-phosphate (PubMed:11598300, PubMed:17905878, PubMed:6749498). Can also catalyze the double aldol condensation of three acetaldehyde molecules, leading to the formation of 2,4,6-trideoxyhexose (Ref.5). 2-deoxy-D-ribose 5-phosphate = acetaldehyde + D-glyceraldehyde 3-phosphate Optimum pH is 7.5 for 2-deoxy-D-ribose 5-phosphate cleavage. Carbohydrate degradation; 2-deoxy-D-ribose 1-phosphate degradation; D-glyceraldehyde 3-phosphate and acetaldehyde from 2-deoxy-alpha-D-ribose 1-phosphate: step 2/2. Monomer and homodimer. Belongs to the DeoC/FbaB aldolase family. DeoC type 2 subfamily.