| Autor: |
Michał W. Wieczorek, Marian Mikołajczyk, Fernando Montanari, Wanda H. Midura, S. Grzejszczak, Mauro Cinquini, Janina Karolak-Wojciechowska |
| Rok vydání: |
1994 |
| Předmět: |
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| Zdroj: |
Tetrahedron. 50:8053-8072 |
| ISSN: |
0040-4020 |
| DOI: |
10.1016/s0040-4020(01)85289-3 |
| Popis: |
Chlorination of α-phosphoryl sulfoxides 1 with iodobenzene dichloride and sulfuryl chloride in the presence and in the absence of pyridine and stereochemical investigations of this reaction using (+)-(S)-α-dimethoxyphosphorylmethyl p-tolyl sulfoxide 1a are described. It was found that conversion of 1 to the corresponding α-chloro-α-phosphoryl sulfoxides 2 occurs under the stereochemical control of the sulfinyl group and leads to diastereomeric mixtures. The extent of asymmetric induction at the α-carbon atom and racemization of the chiral sulfinyl centre in 1 depend on the reaction conditions. The structure of the major diastereomer formed in the chlorination of (+)-(S)-1ai.e. (+)-(S)c(S)s-α-chloro-α-dimethoxyphosphorylmethyl p-tolyl sulfoxide 2a was determined by X-ray analysis. The structure was solved by direct methods and refined to R=0.081. The experimental data on chlorination of α-phosphoryl sulfoxides 1 point to retention of the configuration at both chiral centres (C and S) and this stereochemistry can be rationalized assuming addition-elimination mechanism involving the formation of a positively charged ylide as intermediate. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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