- Stereoselective and competitive [1,2]- and [2,3]-wittig rearrangements of allyl heteroarylalkyl ethers
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Several allyl heteroarylalkyl ethers have been synthesized and then deprotonated with nBuLi in THF at -78°C to give lithium derivatives. The lithium-bearing terminus was either the α- or the α′-carbon atom, depending on the associated proton acidity. In the absence of an external electrophile, a sigmatropic rearrangement occurs, generating a new C-C bond. Heteroarylalkyl homoallylic alcohols and allyl heteroarylalkylic alcohols were obtained as products of stereoselective [2,3]- or [1,2]-Wittig rearrangements, respectively. Homoallylic alcohols were obtained in high yields and with fairly good enantiomeric enrichments when the reactions were carried out in toluene with (-)-sparteine as the external chiral ligand.
- Capriati, Vito,Florio, Saverio,Ingrosso, Giovanni,Granito, Catia,Troisi, Luigino
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p. 478 - 484
(2007/10/03)
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