Stereoselective synthesis of spirocyclic cyclopentapyrans by the Pauson-Khand reaction on camphor tethered enynes

2008-12-01
Sezer, Serdar
Gumrukcu, Yasemin
ŞAHİN, Ertan
Tanyeli, Cihangir
An intramolecular Pauson-Khand reaction of camphor tethered enynes derived from homoallyl, homomethallyl and homopropargyl alcohols is described. Homoallyl, homomethallyl, and homopropargyl moieties are easily constructed on the camphor carbonyl group with excellent diastereoselectivity due to endo-face selectivity, and with known stereochemistry. Each enantiomerically pure enyne affords the conformationally most stable diastereomeric spirocyclic cyclopenta[c]pyran ring system.
TETRAHEDRON-ASYMMETRY

Suggestions

Stereoselective synthesis of optically active cyclopenta[c]pyrans and cyclopenta[c]furans by the intramolecular Pauson-Khand reaction
Sezer, Serdar; ŞAHİN, Ertan; Tanyeli, Cihangir (Elsevier BV, 2010-03-16)
An intramolecular Pauson-Khand reaction of enynes derived from homoallyl, homopropargyl, and allyl alcohols is described. 2-Heteroaryl-substituted homoallyl, homopropargyl, and allyl alcohols are easily and efficiently resolved through enzymatic resolution in high ee (91-99%) and with a known stereochemistry. Each enantiomerically enriched enyne derived from homoallyl and homopropargyl alcohols affords the conformationally most stable diastereomeric cyclopenta[c]pyran ring system as the sole product, wherea...
Conformational control on remote stereochemistry in the intramolecular Pauson-Khand reactions of enynes tethered to homoallyl and homopropargyl alcohols
Sezer, Serdar; Ozdemirhan, Devrim; Sahin, Ertan; Tanyeli, Cihangir (Elsevier BV, 2006-11-17)
An intramolecular Pauson-Khand reaction of enynes derived from homoallyl and homopropargyl alcohols is described. 2-Furyl substituted homoallyl and homopropargyl alcohols are easily and efficiently resolved through enzymatic resolution in a high ee (93-99%) with a known stereochemistry. Each enantiomerically enriched enyne affords the conformationally most stable diastereomeric cyclopenta[c]pyran ring system.
Stereoselective synthesis of optically active cyclopenta[c]pyridines and tetrahydropyridines
SEZER, Serdar; GÜMRÜKÇÜ, Yasemin; BAKIRCI, Irem; Unver, M. Yagiz; Tanyeli, Cihangir (2012-05-15)
The intramolecular Pauson-Khand and ring closing metathesis (RCM) reactions of nitrogen containing chiral enynes and dienes are described. The enyne and diene systems comprised of N-propargylated and N-allylated units are constructed on chiral homoallylic or homopropargylic alcohol backbones, respectively, via S(N)2 and/or modified Mitsunobu reactions. The racemic homoallylic and homopropargylic alcohol derivatives were successfully resolved in high ee (93-99%) by applying chemoenzymatic methods using vario...
Stereoselective synthesis of gamma-lactone fused cyclopentanoids
Gumus, Aysegul; Tanyeli, Cihangir (2012-10-15)
The stereoselective synthesis of gamma-lactone fused cyclopentanoids applying chemoenzymatic methods is described. rac-2-Hydroxymethyl-1,4,5,6-tetrachloro-7,7-dimethoxybicyclo[2.2.1]hept-5-ene and rac-2-hydroxymethyl-1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hept-5-ene were successfully resolved by Candida rugosa lipase (CRL), to afford enantiomerically enriched products with an ee of 94 and 97%, respectively. The enantiomerically enriched acetates were then subjected to ruthenium and/or cerium catalyzed oxidatio...
Stereoselective Synthesis of Bishomo-inositols as Glycosidase Inhibitors
Baran, Arif; Balcı, Metin (2009-01-02)
For the synthesis of various bishomo-inositol derivatives, 1,3,3a,7a-tetrahydro-2-benzofuran was used as the key compound. For further functionalization of the diene unit, the diene was subjected to photooxygenation, epoxidation, and cis-hydroxylation reactions. The endoperoxide linkage was cleaved by thiourea. The remaining double bond was subjected to epoxidation and cis-hydroxylation reactions. The epoxide rings and tetrahydrofuran rings formed were opened by acid-catalyzed reaction with sulfamic acid. T...
Citation Formats
S. Sezer, Y. Gumrukcu, E. ŞAHİN, and C. Tanyeli, “Stereoselective synthesis of spirocyclic cyclopentapyrans by the Pauson-Khand reaction on camphor tethered enynes,” TETRAHEDRON-ASYMMETRY, pp. 2705–2710, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/43985.