Transesterification is a synthetic chemistry strategy promoted in acid or alkaline conditions, yielding a structural diversity of organic compounds. Epoxythymols comprise a class of chiral natural compounds with biological relevance, and literature describes their chiral purity loss during acid transesterification reactions. This work reports the basic transesterification of the natural derivative (8S)-10-benzoxy-8,9-epoxy-6-hydroxytimol under alkaline conditions. Herein, the formation of (8S)-10-benzoxy-6-isobutyryloxy-8,9-epoxitimyl isobutyrate is gained, avoiding the loss of optical purity. ¹H NMR-BINOL experiments revealed the enantiomeric purity of the product reaction. These results highlight that the implemented strategy promotes transesterification, preserving the optical purity.