Synthesis of the C17-C25 subunit of lasonolide A utilizing a Tsuchihashi-Yamamoto type rearrangement

An efficient synthesis of the C₁₇-C₂₅ subunit resident in (−)-lasonolide A is reported herein. The key reaction features that were utilized include a Tsuchihashi-Yamamoto type rearrangement and Molander-Reformatsky SmI₂ mediated intramolecular aldol reaction sequence. Lastly, a diastereoselective target oriented β-C-glycoside formation sequence via an oxocarbenium reduction completed the stereochemistry required for the completion of the C₁₇-C₂₅ segment of (−)-lasonolide A.