HuagongsheHuagongshe Chemie-Druckbericht · Nur für Forschungszwecke
Lithium Hydroxide → (1R,2R)-2-(4-bromophenyl)Cyclopropanecarboxylic acid
Beteiligte Stoffe
| Rolle | Name | HCID | Einwaage |
|---|---|---|---|
| Edukt | Lithium Hydroxide | HCID 3939 | — |
| Edukt | 4-Bromostyrene | HCID 16263 | — |
| Edukt | Diazoacetate | HCID 21863207 | — |
| Edukt | ethyl (1R,2R)-2-(4-bromophenyl)cyclopropanecarboxylate | HCID 66578655 | — |
| Produkt | (1R,2R)-2-(4-bromophenyl)Cyclopropanecarboxylic acid | HCID 12586658 | — |
| Produkt | ethyl (1R,2S)-2-(4-bromophenyl)cyclopropane-1-carboxylate | HCID 66578128 | — |
Reaktionsschritte
Another alternative is an enantioselective cyclopropanation using for example a bis-oxazoline chiral ligand/copper complex and diazoacetate (Evans et al. J. Am. Chem. Soc. 1991, 113, 726) to prepare optically active ethyl 2-(trans)-(4-bromophenyl)cyclopropanecarboxylate from 4-bromostyrene. Selective hydrolysis of the mixture of cis and trans isomer with LiOH (1 eq based on the trans ester) gave 2-(trans)-(4-bromophenyl)cyclopropanecarboxylic acid and ethyl 2-(cis)-(4-bromophenyl)cyclopropanecarboxylate which can be used in EXAMPLE 8.
Herkunft & Nachweise
| DOI | 10.6084/m9.figshare.5104873.v1 |
|---|---|
| Patentnummer | US07238706B2 |
| Quelldatensatz | uspto-grants-2007_07 |
| ORD ID | ord-3304206f5dce4347b5e856e4819413d0 |
| Quellennotiz | uspto-grants-2007_07 |