Furthermore, we trained a single-step template-based retrosynthesis prediction model on only ring-forming reactions based on the approach used by Thakkar et al. in 'Ring Breaker'. Our dataset comprised reactions from the Ring dataset and ring formations extracted from the General (USPTO 5 ) dataset. Atom-mapping of reaction data was conducted using RXNMapper, and reaction templates were subsequently extracted using RDKit 39 and RDChiral. We used TensorFlow 41 to construct the multilabel classification neural network for prediction. The selected hyperparameters are provided in the SI §S2.