In a typical reaction, steroidal β-formyl enamide (1) and nitromethane were mixed with pyrrolidine and irradiated in a Synthwave Microwave Module 402 (Prolabo) at operating frequency of 2450 MHz and 80% of output power for 8-10 minutes (Scheme [1] ). The work up of the reaction mixture did not afford the expected nitro-aldol or nitro-olefin product; rather it afforded a cyclised product 5′-nitro-6′-methyl-pyrido-(17,16-b)-androst-5-ene (10) in 90% yield. The product was ...
