This week’s problem is an set of reactions excerpted from the synthesis of a polyprenylated acylphloroglucinol(PPAP) natural compound Nemorosone performed by Nakada and coworkers. The illustrated sequence effectively constructed the bicyclo[3.3.1]nonane core from an swiftly prepared diazoketone with a synthetically reasonable yield of 47%.
Identify all the synthetic intermediates while disregarding absolute stereochemistry, since the desymmetrization was later achieved by applying a chiral bisoxazoline instead of the achiral one shown above.
For reference:
Uwamori, M., Saito, A., & Nakada, M. (2012).
“Stereoselective Total Synthesis of Nemorosone.”
The Journal of Organic Chemistry, 77(11), 5098–5107.
doi:10.1021/jo300646j