As usual we are a bit late on this, but here is this month's molecule:
which is known as (4R,5S,6R)-4,6-diacetylhygrophorone A12, and is an antifungal natural product isolated from mushrooms of the genus Hygrophorus.
As far as I know this compound has not yet been synthesised in the lab, but has been isolated and its relative configuration assigned by NMR measurements in anisotropic media.
The criteria are the same as for the last challenge I posted:
- the synthesis must be enantioselective; and
- no more than one chiral centre may be purchased in the form of a building block. (Chiral catalysts, ligands, auxiliaries, etc. do not fall under this rule.)
Otherwise, any commercially available starting material (as usual, in the Sigma–Aldrich catalogue) is fair game.
(1) Schmidts, V.; Fredersdorf, M.; Lübken, T.; Porzel, A.; Arnold, N.; Wessjohann, L.; Thiele, C. M. RDC-Based Determination of the Relative Configuration of the Fungicidal Cyclopentenone 4,6-Diacetylhygrophorone A12. J. Nat. Prod. 2013, 76 (5), 839–844. DOI: 10.1021/np300728b.
(2) The absolute stereochemistry was not assigned in ref 1, so you may synthesise either enantiomer. Obviously, though, that doesn't make a difference to the design of the synthetic route, so I have arbitrarily decided to display this enantiomer (following ref 1).