Progress Toward the Total Synthesis of Garsubellin A and Structurally Related Phloroglucin Natural Products

Progress toward the polyprenylated phloroglucin garsubellin A is presented. A highly diastereoselective single-step cyclization reaction provides access to the bicyclo[3.3.1]nonane core of this natural product. Further elaboration to a more functionalized analog involves a sequential Claisen rearrangement/Grubbs olefin cross metathesis strategy. Additionally, the feasibility of this strategy toward the preparation of the bis-quaternary carbon array found at the bridgehead positions of the phloroglucinol natural products is demonstrated. Enantioselective strategies and model studies will also be discussed.