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Synlett 2002(1): 0077-0080
DOI: 10.1055/s-2002-19339
LETTER
© Georg Thieme Verlag Stuttgart · New York

Concise Synthesis of (+)-β-Benzyl γ-Butyrolactones from Butynediol

Stefan Kamlagea,, Michael Sefkowa, Nicole Zimmermannb,, Martin G. Peter*a
a Institut für Organische Chemie und Strukturanalytik, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Golm, Germany
b Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
e-Mail: peter@serv.chem.uni-potsdam.de;
Further Information

Publication History

Received 15 October 2001
Publication Date:
01 February 2007 (online)

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Abstract

The synthesis of optically active β-benzyl-γ-butyrolactones from butynediol via four transition metal catalysed reactions is reported. Key reactions are the hitherto unknown enantioselective hydrogenation of 2-benzyl-2-buten-1,4-diols using Ir(I)-phosphinooxazoline catalysts and the regiocontrolled oxidation of the resulting 2-benzyl-1,4-butanediols to the β-substituted butyro-lactones.

Key words

(+)-β-benzyl γ-butyrolactones - butynediol - enantioselective hydrogenation

1

New address: AVACON Internet-Service, Fürstenwalder Damm 472, d-12587 Berlin, Germany.

2

Current address: The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.

15

Representative Experimental Procedure for 2-Benzyl-butan-1,4-diol (5a):
Diol 6a (1.035 g, 5.81 mmol) was dissolved in dry dichloromethane (44 mL). [Ir(COD)(PHOX)]BARF C (273 mg, 3 mol%), was added. The mixture was hydrogenated with 100 bar H2 for 3 h using an autoclave. The solvent was removed and the reaction product purified by flash chromatography (silica gel, EtOAc-light petroleum ether, 2:1). Diol 5a was obtained in 0.95 g (92%) as pale yellow oil (ee: 82%). 1H NMR: δ = 1.58-1.69 m (2 H, H-3), 1.95-2.04 m (1 H, H-2), 2.53 dd (1 H, J = 7.3 and 13.6, H-2"), 2.63 dd (1 H, J = 7.5 and 13.6, H-2"), 3.34 (br s, 2 H, 2 × OH), 3.42-3.76 m (4 H, H-1 and H-4), 7.15-7.30 m (5 H, arom.). 13C NMR: δ = 35.2, 38.1, 41.2, 60.9, 65.5, 126.0, 128.3, 129.0, 140.2. IR: 3344, 1042 cm-1.