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Synthesis 2005(18): 3147-3151  
DOI: 10.1055/s-2005-916025
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis and Derivatization of Bis-nor Wieland-Miescher Ketone

Tõnis Kanger*a, Kristin Raudlaa, Riina Aava, Aleksander-Mati Müüriseppa, Tõnis Pehkb, Margus Loppa
a Department of Chemistry, Faculty of Science, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
Fax: +372(6)202828; e-Mail: kanger@chemnet.ee;
b National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia
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Publication History

Received 3 May 2005
Publication Date:
16 September 2005 (online)

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Abstract

An efficient synthesis of bis-nor Wieland-Miescher ketone and its derivatives starting from commercially available 2-allyl-2-methylcyclopenta-1,3-dione is described.

Key words

alkylation - carbocycles - cyclization - epoxidation - Wittig reaction

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6-Allyl-6-methyldihydro-2H-pyran-2,5 (6H)-dione: 1H NMR (CDCl3): δ = 5.72 (m, 1 H, =CH), 5.13 and 5.15 (m, 2 H, =CH2), 2.84 and 2.88 (m, 2 H, H-3), 2.73 and 2.60 (m, 2 H, H-4), 2.65 and 2.45 (tdd each, 2 H, J = 0.9, 0.9, 7.4, 14.1 Hz, CH 2CH=CH2), 1.48 (s, 3 H, CH3). 13C NMR (CDCl3): δ = 207.23 (C-5), 169.24 (C-2), 130.35 (=CH), 121.06 (=CH2), 88.71 (C-6), 43.20 (CH2CH=CH2), 33.96 (C-4), 28.04 (C-3), 24.92 (CH3).

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Alternatively, a crystalline phosphonium salt can be isolated by filtration remaining by-product into solution. However, this isolation decreases the overall yield of compound 2 from 79% to 64%.