T. Tsuchimoto, T. Ainoya, K. Aoki, T. Wagatsuma, E. Shirakawa
SHORT COMMUNICATION
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[12] After consumption of 1a upon reaction with 2a was confirmed,
5a was added to the reaction mixture. Other entries using
method A also were carried out in a similar way.
[13] The contamination of α-isomer 7 in several three-component
reactions is likely to be related to the increasing content of
α,αЈ-isomers among the remaining DPAs during the reaction
(Table 2). For example, before and after the addition of 2-meth-
ylfuran (5a) in the reaction of Entry 1, the ratio of β,βЈ-, α,βЈ-
, and α,αЈ-DPA changed from 86:13:1 to 82:11:7 (10 min later)
and then to 78:10:12 (20 min later).
Received: March 7, 2009
Published Online: April 14, 2009
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Eur. J. Org. Chem. 2009, 2437–2440