starting with aldehydes 3, in good to excellent yield is described herein. This novel approach was carried out by the Henry reaction of 3 with NH4OAc and nitroalkanes (MeNO2 or EtNO2), aerobicWacker-type oxidation of the resulting nitroalkenes 4, followed by K2CO3-promoted intramolecular Michael cyclization in modest to good yields.
本文描述了从醛3开始以良好或优异的产率向异色酮6合成的途径。这种新方法是通过3与NH 4 OAc和硝基烷(MeNO 2或EtNO 2)的亨利反应,所得硝基烯烃4的好氧Wacker型氧化,然后由K 2 CO 3促进的分子内迈克尔环化而进行的。高产。
reaction of aldehydes 3a–e with nitroalkanes and NH4OAc at reflux, reduction of the resulting nitroalkenes 4a–h with LAH at rt followed by protection with K2CO3 and PhSO2Cl at rt, one-pot oxidative cleavage annulation of olefins 5a–h with the one-pot combination of OsO4/NaIO4 at reflux, and hydrogenation of the corresponding enamines 6a–f. Aldehydes 3a–e was prepared from 2a and 2b in moderate yield of