The systematic approach generates 27,577 reactions, involving 4,095 fragments, that can be made by forming and breaking three bonds but constrain the total number of changes to five. Only 1,138 of the 4,095 fragments are stable upon PM3 geometry optimisation, resulting in 9,056 reactions for which the reaction energy can be computed. GFN2-xTB barriers are estimated for the 1,583 reactions that have reaction energies below 30 kcal/mol and the 64 reaction with estimated barriers less than 50 kcal/mol are refined at the DFT level and verified with an IRC. This results in four reactions connecting 3-hydroperoxypropanal to products: the three reactions with barriers below 50 kcal/mol previously identified by Grambow et al. and a previously undiscovered reaction (Figure ) with a barrier of 62 kcal/mol.