Synthesis of Open-Chain 2,3-Disubstituted 4-nitroketones by Diastereoselective Michael-addition of (E)-Enamines to (E)-Nitroolefins. A Topological Rule for C,C-Bond Forming Processes between Prochiral Centres

Article abstract of DOI:10.1002/hlca.19810640518

The Michael-additions of aliphatic , alicyclic, and arylsubstituted nitroolefins and enamines lead to γ-nitroketones 3 in good chemical and excellent (>90percent) diastereomeric yields (see Table 1).The known threo-configuration of one type of adducts 3 (entries 8, 10 and 11 of Table 1) can be arrived at by assuming the approach 8 of the Michael-acceptor and -donor; the reaction follows a topological rule, which is formulated and which is applicable to such diverse reactions as the diene synthesis, cyclopropanations, carbonyl olefinations and methylenations, aldol- and nitroaldol-type additions, as well as additions of lithium, boron, and chromium derivatives to aldehydes (see 9, 10, 11, and Table 2).