Synlett 2018; 29(14): 1887-1891
DOI: 10.1055/s-0037-1609559
letter
© Georg Thieme Verlag Stuttgart · New York

Stereoselective Synthesis of 4-Substituted 2,4-Dichloro-2-butenals by α- and γ-Regioselective Double Chlorination of Dienamine Catalysis

Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nakagami, Nishihara, Okinawa 903-0213, Japan   Email: arimitsu@sci.u-ryukyu.ac.jp
,
Kazuto Terukina
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nakagami, Nishihara, Okinawa 903-0213, Japan   Email: arimitsu@sci.u-ryukyu.ac.jp
,
Tatsuro Ishikawa
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nakagami, Nishihara, Okinawa 903-0213, Japan   Email: arimitsu@sci.u-ryukyu.ac.jp
› Author Affiliations

Part of this research was financially supported by MEXT/JSPS KAKENHI, Grant No. JP17K14451.
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Publication History

Received: 11 April 2018

Accepted after revision: 13 June 2018

Publication Date:
20 July 2018 (online)


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Abstract

The l-proline-catalyzed reaction of enolizable α,β-unsaturated aldehydes with N-chlorosuccinimide (NCS) gave the corresponding 4-substituted 2,4-dichloro-2-butenals with moderate yields and excellent diastereoselectivities (Z/E = >20/1) through consecutive double chlorination at the α- and γ-positions of the dienamine intermediate. The corresponding 2,4-dichloro-2-butenals contain a multireactive 1,3-dichloro allylic unit useful for the construction of Z-vinyl chlorides; the chloride on the allylic position was replaced with mild nucleophiles such as MeOH and EtOH via an SN2 substitution reaction, and its aldehyde moiety was used as a synthetic handle and transformed into an alcohol or a vinyl group. All products obtained after those synthetic manipulations maintained excellent diastereoselectivities (Z/E = >20/1).

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