152. “Efficient Enantioselective Syntheses of Sertraline, 2-Epicatalponol and Catalponol from Tetralin-1,4-dione”
     A. Enriquez Garcia, S. Ouizem, X. Cheng, P. Romanens, E.P. Kündig,
     Adv. Synth. Catal. 2010, 352, 2306-2314.

Tetralin-1,4-dione, the stable tautomer of dihydroxynaphthalene, was reduced with catecholborane in the presence of 3,3-diphenyl-1-butyltetrahydro-3H-pyrrolo[1,2-c][1,3,2]oxazaborole as catalyst to give enantiomerically highly enriched 4-hydroxy-1-tetralone (99% ee) in an efficient one-pot procedure. The R-enantiomer provided a rapid access to sertraline while the S-enantiomer was converted into 2-epicatalponol and catalponol. A more selective enantioselective route to the antithermitic catalponol made use of the planar chiral tricarbonylchromium complex of hydroxytetralone. Its precursor chromium(tricarbonyl)[η⁶-(1-4,4a,8a)-tetralin-5,8-dione] was obtained via direct complexation of 1,4-dihydroxynaphthalene using chromium(tricarbonyl)- tris(ammonia) and boron trifluoride etherate as source of the chromium(tricarbonyl) fragment. Enolate prenylation was best carried out in the presence of a tetraamine ligand. Complete inversion of the stereogenic center bearing the prenyl group of the initially obtained tetralone complex was achieved via enolate formation followed by protonation.

DOI : 10.1002/adsc.201000384 

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