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
easily available from dihydropyranylcarbene complexes, evolve under mild oxidative conditions to form new functionalized compounds through an oxidative rearrangement process. Depending on the substitution of the starting material, different rearranged final products including cyclopentanone, cyclopentenone, spiroketal and polycyclic derivatives are easily available.