title: A concise synthetic route to the stereotetrad core of the briarane diterpenoids.
abstract: A concise synthesis (under 10 steps) of the stereotetrad core of the briarane diterpenoids is reported. This approach harnesses the unique reactivity of salicylate ester derived 2,5-cyclohexadienones to quickly build complexity. In particular, a highly diastereoselective acetylide conjugate addition/β-ketoester alkylation sequence was used to set the relative configuration of the C1 (quaternary) and C10 (tertiary) vicinal stereocenters. The sterochemical outcome of the β-ketoester alkylation appears to be governed by torsional steering in the transition state.
authors: †Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.
authors: Nicholas G
authors: NG
authors: Moon
authors: †Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.
authors: Andrew M
authors: AM
authors: Harned
mesh_terms: D000478:Alkylation; D002384:Catalysis; D053138:Cyclohexenes / Q000737:chemistry*; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D053138:Cyclohexenes; D004224:Diterpenes; C507608:cyclohexadienone