Synthesis of Methyl ο-(5-Oxo-1-cyclopentenyl)alkanoates Starting from 2-Nitrocycloalkanones

Article abstract of DOI:10.1002/hlca.19870700207

A convenient synthesis of methyl ο-(5-oxo-1-cyclopentenyl)alkanoates 1 is described. 2-Nitrocycloalkanones 2 are converted to 2-(3,3-dimethoxypropyl)-2-nitrocycloalkanones 4.Treatment of 4 with MeOH/MeONa led to the ring-opened nitronates 5 which underwent a Nef reaction to form the corresponding oxo derivatives 6.Partial hydrolysis of 6 followed by base-catalyzed aldol reaction gave the desired products in high yields.