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Multigramme synthesis and asymmetric dihydroxylation of a 4-fluorobut-2E-enoate

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journal contribution
posted on 13.07.2015, 09:43 by J. A. B. Laurenson, J. A. Parkinson, J. M. Percy, G. Rinaudo, Ricard Roig
Esters of crotonic acid were brominated on a multigramme scale using a free radical procedure. A phase transfer catalysed fluorination transformed these species to the 4-fluorobut-2E-enoates reproducibly and at scale (48–53%, ca. 300 mmol). Asymmetric dihydroxylation reactions were then used to transform the butenoate, ultimately into all four diastereoisomers of a versatile fluorinated C4 building block at high enantiomeric-enrichment. The (DHQ)2AQN and (DHQD)2AQN ligands described by Sharpless were the most effective. The development and optimisation of a new and facile method for the determination of ee is also described; 19F{1H} spectra recorded in d-chloroform/diisopropyl tartrate showed distinct baseline separated signals for different enantiomers.

History

Citation

Beilstein Journal of Organic Chemistry, 2013, 9, pp. 2660–2668.

Version

VoR (Version of Record)

Published in

Beilstein Journal of Organic Chemistry

Publisher

Beilstein-Institut

issn

1860-5397

Acceptance date

08/11/2013

Copyright date

2013

Available date

13/07/2015

Publisher version

http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?publicId=1860-5397-9-301

Language

en