Synlett 2008(5): 653-654  
DOI: 10.1055/s-2008-1042806
LETTER
© Georg Thieme Verlag Stuttgart · New York

Facile Aromatic Claisen Rearrangement Catalysed by Tin(IV) Chloride

Debayan Sarkar, Ramanathapuram V. Venkateswaran*
Department of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
Fax: +91(33)24732805; e-Mail: ocrvv@iacs.res.in;
Further Information

Publication History

Received 24 September 2007
Publication Date:
26 February 2008 (online)

Abstract

Allyl aryl ethers undergo facile Claisen rearrangement under mild conditions catalysed by tin(IV) chloride.

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7-Methoxy-2,5-dimethyl-dihydrobenzofuran (Entry 10)Obtained as a colourless solid. Crystallised from Et2O-PE, mp43-44 °C. 1H NMR (300 MHz, CDCl3): δ = 1.51 (d, J = 11.5 Hz, 3 H), 2.28 (s, 3 H), 3.02 (dd, A of ABX, J AB = 13.8 Hz, 1 H), 3.04 (dd, B of ABX, J BA = 13.8 Hz, 1 H), 3.87 (s, 3 H), 4.40 (sext, X of ABX, J AX = J BX = 6.6 Hz,1 H), 6.58 (s, 1 H), 6.60 (s, 1 H). 13C NMR (75 MHz, CDCl3): δ = 21.2, 24.9, 41.2, 56.0, 57.7, 110.3, 123.6, 123.8, 128.8, 141.6, 146.2. HRMS (ES+ve): m/z calcd for C11H14O2 [M + Na]+: 201.0892; found: 201.0889.