Synthese von ω‐(5‐Oxo‐1‐cyclopentenyl)alkansäure‐methylestern aus 2‐Nitrocycloalkanonen

Abstract

Synthesis of Methyl ω‐(5‐Oxo‐1‐cyclopentenyl)alkanoates Starting from 2‐Nitrocycloalkanones A convenient synthesis of methyl ω‐(5‐oxo‐1‐cyclopentenyl)alkanoates 1 is described. 2‐Nitrocycloalkanones 2 are converted to 2‐(3,3‐dimethoxypropy1)‐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 followed by base‐catalyzed aldol reaction gave the desired products in high yields.