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Synfacts 2010(9): 0982-0982  
DOI: 10.1055/s-0030-1257874
Synthesis of Natural Products and Potential Drugs
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of (-)-(S,S)-Clemastine

Contributor(s): Philip Kocienski
A. M. Fournier, R. A. Brown, W. Farnaby, H. Miyatake-Ondozabal, J. Clayden*
University of Manchester, UK
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Publication History

Publication Date:
23 August 2010 (online)

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Significance

Clemastine (meclastine) is a selective histamine H1 antagonist that is marketed as an antihistamine. It also has anticholinergic and sedative effects. The (R,R)-isomer is the most ­active of the four possible diastereoisomers of clemastine. The following synthesis of (S,S)-clemastine features a novel 1,4-aryl migration of a lithiated carbamate E and may proceed via the spirocyclic carbanion F.