| Autor: |
James A. B. Laurenson, John A. Parkinson, Jonathan M. Percy, Giuseppe Rinaudo, Ricard Roig |
| Jazyk: |
angličtina |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
Beilstein Journal of Organic Chemistry, Vol 9, Iss 1, Pp 2660-2668 (2013) |
| Druh dokumentu: |
article |
| ISSN: |
1860-5397 |
| DOI: |
10.3762/bjoc.9.301 |
| Popis: |
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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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