Journal article
Synthesis of Nonracemic Dimethyl α-(Hydroxyfarnesyl)phosphonates via Oxidation of Dimethyl Farnesylphosphonate with (Camphorsulfonyl)oxaziridines
Journal of organic chemistry, Vol.64(2), pp.388-393
01/22/1999
DOI: 10.1021/jo980984z
Abstract
Several strategies for synthesis of nonracemic dimethyl α-(hydroxyfarnesyl)phosphonate and the parent phosphonic acid have been explored. Separation of diastereomeric derivatives prepared by esterification of racemic α-hydroxy phosphonate with (S)-(+)-O-methylmandelic acid was possible, and these diastereomers could be assigned absolute stereochemistry on the basis of literature precedent. However, hydrolysis to the α-hydroxy phosphonic acid was accompanied by extensive isomerization. Addition of a nonracemic phosphonamidite to farnesal also gave nonracemic material, but again hydrolysis was problematic. Oxidation of dimethyl farnesylphosphonate anion with nonracemic (camphorsulfonyl)oxaziridines was shown to be regio- and stereoselective for formation of the α-hydroxy phosphonate. Enantiomeric excess of ∼70% ee was established by conversion of the oxidation products to their (S)-(+)-O-methylmandelate derivatives. Although hydrolysis of these methyl esters was accompanied by extensive racemization, both enantiomers of α-(hydroxyfarnesyl)phosphonic acid were obtained in low ee by this strategy.
Details
- Title: Subtitle
- Synthesis of Nonracemic Dimethyl α-(Hydroxyfarnesyl)phosphonates via Oxidation of Dimethyl Farnesylphosphonate with (Camphorsulfonyl)oxaziridines
- Creators
- Diana M CermakYanming DuDavid F Wiemer
- Resource Type
- Journal article
- Publication Details
- Journal of organic chemistry, Vol.64(2), pp.388-393
- Publisher
- American Chemical Society
- DOI
- 10.1021/jo980984z
- ISSN
- 0022-3263
- eISSN
- 1520-6904
- Language
- English
- Date published
- 01/22/1999
- Academic Unit
- Chemistry; Neuroscience and Pharmacology
- Record Identifier
- 9983985837002771
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