REDUCTION OF NITRONATE ADDUCTS FROM RMgX AND 1-METHOXY-4-NITRO-NAPHTHALENE TO OXIMES OR AMINES BY TRIVALENT PHOSPHORUS REAGENTS

Article abstract of DOI:10.1016/S0040-4020(01)91493-0

The reduction of nitronate adducts from 1-methoxy-4-nitronaphthalene and Grignard reagents (CH3MgX, PhCH2CH2MgX, i-C3H7MgX, c-C6H11MgX and t-C4H9MgX) with hexamethyl phosphorous triamide and phosphorous trichloride is reported.With the former reagent the reaction is chemio and stereoselective and only the E-oxime is recovered being the E-2-alkyl-4-methoxy-1(2H)naphthalenone oximes and the E-2-alkyl-2,3-dihydro-1,4-naphthoquinone-1-oximes obtained after quenching with NH4Cl and HCl respectively.Oxime stereochemistry is assigned by LIS values caused by Eu(dpm)3 on (13)C signals of 2-methyl-4-methoxy-1-(2H)naphthalenone oxime and 2-methyl-2,3-dihydro-1,4-naphthoquinone-1-oxime.Complete reduction to amines is obtained with phosphorous trichloride.