Solvent-Controlled Diastereoselective Synthesis of Cyclopentane Derivatives by a [3 + 2] Cyclization Reaction of α,β-Disubstituted (Alkenyl)(methoxy)carbene Complexes with Methyl Ketone Lithium Enolates
作者:José Barluenga、Jorge Alonso、Francisco J. Fañanás
DOI:10.1021/ja029170x
日期:2003.3.1
11 with methyl ketone lithium enolates 2 leads to the corresponding five-membered carbocyclic compounds 4 or diast-4 and 12. The influence of the solvent and/or cosolvent (PMDTA), which turned out to be crucial to direct the reaction to 4 or diast-4, is studied, and a tentative mechanism according to these facts is proposed. In addition, the reaction of carbene complex 1a with alkynyl methyl ketone
Diastereoselective Synthesis of Cycloheptadienol Derivatives by a Formal [5+2] Carbocyclization Reaction of α,β,γ,δ-Diunsaturated (Methoxy)carbene Complexes with Methyl Ketone Lithium Enolates
作者:José Barluenga、Jorge Alonso、Francisco J. Fañanás、Javier Borge、Santiago García-Granda
DOI:10.1002/anie.200460547
日期:2004.10.18
Diastereoselective Synthesis of Five- and Seven-Membered Rings by [2+2+1], [3+2], [3+2+2], and [4+3] Carbocyclization Reactions of β-Substituted (Alkenyl)(methoxy)carbene Complexes with Methyl Ketone Lithium Enolates
作者:José Barluenga、Jorge Alonso、Francisco J. Fañanás
DOI:10.1002/chem.200500164
日期:2005.8.19
derived from a formal [2+2+1] carbocyclization reaction. However, the lithium enolates of acetone and tungsten complexes furnish formal [3+2+2] carbocyclization products. In the case of alkynyl methyl ketone lithium enolates, competitive formal [2+2+1] and [3+2] carbocyclization reactions occur and 1,3-cyclopentanediol and 3-cyclopentenol derivatives are formed. Conversely, alkenyl methyl ketone lithium enolates