Synthesis, Stereochemical Confirmation, and Derivatization of 12(S),16ϵ‐Dihydroxycleroda‐3,13‐dien‐15,16‐olide, a Clerodane Diterpene That Sensitizes Methicillin‐Resistant Staphylococcus aureus to β‐Lactam Antibiotics

Abstract Over the past decades, antibiotic resistance has grown to a point where orthogonal approaches to combating infections caused by resistant bacteria are needed. One such approach is the development of non‐microbicidal small molecules that potentiate the activity of conventional antibiotics, termed adjuvants. The diterpene natural product 12(S),16ϵ‐dihydroxycleroda‐3,13‐dien‐15,16‐olide, which we refer to as (−)‐LZ‐2112, is known to synergize with oxacillin against methicillin‐resistant Staphylococcus aureus (MRSA). To explore this activity, (−)‐LZ‐2112 was synthesized and the structure confirmed through X‐ray analysis. Preliminary structure–activity relationship studies following the synthesis of several analogs identified key structural elements responsible for activity and indicate that scaffold simplification is possible. A preliminary mode of action study suggests mecA plays a role in the adjuvant activity of (−)‐LZ‐2112.