Enantioselective synthesis of carba- l -furanose precursors of carbanucleosides, using ring-closing metathesis
作者:Isabelle Gillaizeau、Steve Charamon、Luigi A Agrofoglio
DOI:10.1016/s0040-4039(01)01905-0
日期:2001.12
Carba-l-sugars were synthesized in seven steps from known tetra-O-benzyl-d-galactopyranose (3). The synthesis of cyclopentene ring has been accomplished via a ring-closingmetathesis step. Schrock's catalyst was employed on the unique diene, key intermediate (5), to provide the cyclopentene derivative (7), a versatile intermediate for the synthesis of carbocyclic nucleosides.
Synthesis of l-cyclopentenyl nucleosides using ring-closing metathesis and palladium-mediated allylic alkylation methodologies
作者:Luigi A. Agrofoglio、Franck Amblard、Steven P. Nolan、Steve Charamon、Isabelle Gillaizeau、Thomas A. Zevaco、Pierre Guenot
DOI:10.1016/j.tet.2004.07.009
日期:2004.9
synthesis of l-cyclopentenyl nucleosides is described. The key intermediate (+)-cyclopentenyl alcohol (8) was prepared from methyl-α-d-galactopyranoside 1 using a ring closing metathesis reaction. Transformation of the allylicalcohol 8 into the allylicacetate (9) or carbonate (10), allows their coupling with purine and pyrimidine bases under Pd(0)-catalyzed Tsuji–Trost allylic alkylation's to yield 12a–c