Stereoselective synthesis and molecular modeling of chiral cyclopentanes.
The reaction of 3-methyseleno-2-methylselenomethyl-propene with benzyl 2,3-anhydro-4-O-triflyl-β-L-ribopyranoside provides a major convenient enantiomeric product of 1-methylene-(benzyl3,4-dideoxy-α-D-arabinopyranoso)-[3,4-c]-cyclopentane, with benzyl-2,3-anhydro-4-deoxy-4-C-(2-methyl- propen-3-yl)-α-D-lyxopyranoside as a minor product. While the reaction of 3-methyseleno-2-[methylselenomethyl]-propene with benzyl 2,3-anhydro-4-O-triflyl-α-D-ribopyranoside produces a good yield of benzyl-2,3-anhydro-4-deoxy-4-C-(2-methylpropen-3-yl)-α-D-lyxo-pyranoside. Molecular modeling and molecular dynamics simulations indicate that the intermediate in the reaction of the β-L sugar frequently occupies an optimal conformation that leads to the formation of cyclopentane, while the intermediate in the reaction of the α-D sugar has a very small probability. The results point to the dominant role of the β-L sugar intermediate in controlling the cyclopentane formation.
Chemistry Department, College of Science, Sultan Qaboos University, Muscat, Oman. Electronic address: jalil@squ.edu.om.
Raid J
RJ
Abdel-Jalil
Abteilung für Theoretische Chemische Biologie, Institut für Physikalische Chemie, Karlsruher Institut für Technologie, D-76131 Karlsruhe, Germany.
Thomas
T
Steinbrecher
Chemistry Department, College of Science, Sultan Qaboos University, Muscat, Oman.
Thuraya
T
Al-Harthy
Department of Chemistry of the Natural Products, University of Naples Federico II, Napoli, Campania, Italy.
Ahmed
A
Mahal
Chemistry Department, College of Science, Sultan Qaboos University, Muscat, Oman.
Osama K
OK
Abou-Zied
IFIB - Interfakultäres Institut für Biochemie, University of Tuebingen, Tuebingen, Germany.
Wolfgang
W
Voelter
D002244:Carbon / Q000737:chemistry; D003517:Cyclopentanes / Q000138:chemical synthesis*; D008958:Models, Molecular; D016566:Organoselenium Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
C000604611:3-methyseleno-2-methylselenomethyl-propene; D003517:Cyclopentanes; D016566:Organoselenium Compounds; D002244:Carbon
Asymmetric synthesis; Cyclopentane; Molecular dynamics; Molecular modeling