Details

Autor(en) / Beteiligte

• Miranda, Pedro O
• Ramírez, Miguel A
• Martín, Víctor S
• Padrón, Juan I

Titel

The Silylalkyne-Prins Cyclization:  Stereoselective Synthesis of Tetra- and Pentasubstituted Halodihydropyrans

Ist Teil von

• Organic letters, 2006-04, Vol.8 (8), p.1633-1636

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2006

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A new type of Prins cyclization using silylated secondary homopropargylic alcohols and aldehydes yielding tetra- and pentasubstituted dihydropyrans is described. The presence of the trimethylsilyl group in the triple bond favors the Prins cyclization and minimizes the 2-oxonia-[3,3]-sigmatropic rearrangement as a competitive alternative pathway. Ab initio theoretical calculations of the species involved in the rearrangements support the proposed mechanism. The process is highly stereoselective, affording cis-dihydropyran as the only isomer.