The prenyl product present in the original crystal structure 18 is substantially shorter than the natural product, featuring only 20 carbons rather than 100. To extend the prenyl ligand to the full size, facilitating investigations into the substrate egress pathway, we carried out sequential alchemical addition of prenyl units to the end of the chain, starting from the most promising bound state determined from equilibrium simulation (replica 3). The initial GGS with its 20 carbons was fit into the active site by alignment to the original crystal structure. After brief simulation using NAMD 2.14 to eliminate bad contacts and evaluate the performance of the GGS parameters developed using CGenFF. To extend the prenyl chain, an additional prenyl unit was added to the end of the product using psfgen, and an alchemical simulation was performed over 50ns to gradually add the additional 5 carbons to the end of the tail into the S2 site while allowing the growing chain to be flexible within the S2 pocket. Extensions were run repeatedly until the ligand was 20 prenyl units in length. An additional five simulations were run using the fully extended product as a starting point, each for 1µs using the same protocol as above.