Methoxymethylenetriphenylphosphorane
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| IUPAC name
Methoxymethylidene(triphenyl)-λ5-phosphane
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3D model (JSmol)
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| C20H19OP | |
| Molar mass | 306.345 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Methoxymethylenetriphenylphosphorane is a Wittig reagent used for the homologation of aldehydes, and ketones to extended aldehydes.[1] The reagent is generally prepared and used in situ. It has blood-red color, indicative of destabilized ylides.
Preparation
The reagent can be prepared in two steps from triphenylphosphine. The first step is P-alkylation with chloromethyl methyl ether.
- PPh3 + CH3OCH2Cl → [CH3OCH2PPh3]Cl
In the second step, the resulting phosphonium salt is deprotonated.
- [CH3OCH2PPh3]Cl + LiNR2 → CH3OCH=PPh3 + LiCl + HNR2
In place of chloromethyl methyl ether, a mixture of methylal and acetyl chloride can be used.
Wittig–Levine reaction
The use of this chemical as a Wittig reagnt to homologate alehydes and ketones was first reported by Samuel Levine[1] and this process is now sometimes called the Wittig–Levine reaction[2] or the Wittig–Levine homologation[3] The initial product of the Wittig reaction is an enol ether, which can be converted to the aldehyde by acid-catalyzed hydrolysis.
The initial report of the reaction demonstrated its use on the steroid tigogenone.[1]
It was later used in the Wender Taxol total synthesis and the Stork quinine total synthesis.
References
- ^ a b c Levine, Samuel G. (1958). "A New Aldehyde Synthesis". Journal of the American Chemical Society. 80 (22): 6150–6151. doi:10.1021/ja01555a068.
- ^ Dukes, Adrian O.; Weerawarna, Pathum M.; Silverman, Richard B. (2025). "Kinetically Controlled aza-Michael/Epimerization Cascade Enables a Scalable Total Synthesis of Putative (+)-Fumigaclavine F". Organic Letters. 27 (36): 10174–10179. doi:10.1021/acs.orglett.5c03284. PMC 12459949. PMID 40864606.
- ^ Türkmen, Yunus E.; Gravel, Michel; Rawal, Viresh H. (2016). "Studies Directed toward the Synthesis of Aspidophytine: Construction of Its Perhydroquinoline Core". The Journal of Organic Chemistry. 81 (21): 10454–10462. doi:10.1021/acs.joc.6b01574. PMID 27525506.