The study from Grambow et al. identified 75 one-step unique reactions starting from 3-hydroperoxypropanal (Table ). However, we were only able to confirm 69 of the reactions by IRC starting from the transition state (TS) geometries supplied by the authors in SI (missing R10, R12, R31, R32, R34, and R62 in Table ). To compare the product molecules our algorithms produce to those of Grambow et al. we construct a set of atom-mapped SMILES strings with a consistent (arbitrary) atom ordering. It is important to use atom-mapped SMILES to distinguish different reaction mechanisms that lead to the same product, such as reactions R1-R5 in Table ). In a few cases, such as R15-R17, there are several resonance forms for one of the products and here we select the form with the smallest number of rotatable bonds. This saves as much 3D structural information as possible and avoids rotation around bonds that are not completely free to rotate during the reaction path estimation. Thus, we use the same atom order for the reactant SMILES that serve as input to our two reaction discovery algorithms. Since the atoms are labelled, all tetrahedral centers including CH 2 and CH 3 groups are chiral (Figure , we refer to "label-induced" chirality as pseudo-chirality hereafter). When using RDKit to convert the SMILES representation to 3D coordinates the algorithm will generate random pseudo-chiralities for CH 2 and CH 3 groups, which represents a problem for TS search algorithms that interpolate between the 3D structures of reactants and products. Thus, we specify an arbitrary pseudo-chirality for each tetrahedral atom in the reactant (Figure ) and make sure that these pseudo-chiralities are maintained where applicable in the products as described below. We hereafter, refer to atom mapped SMILES with added pseudo-chirality information simply as "mapped SMILES". The construction of a mapped SMILES string from a usual SMILES string is done automatically as part of the computational methodology.