Asymmetric Induction at C(β) and C(α) of N-Enoylsultams by Organomagnesium 1,4-Addition/Enolate Trapping

Article abstract of DOI:10.1002/hlca.19870700825

The 1,4-addition of alkylmagnesium chlorides to conjugated N-enoylsultams and subsequent 'enolate trapping' with aq.NH4Cl or MeI/hexamethylphosphoric triamide generated centers of asymmetry at C(β) and/or at C(α) with good to excellent ?-face differentation as demonstrated by the conversions 1->2, 1->4, and 8->9.This holds also for the regioselective 1,4-addition of EtMgCl to a dienosultam (15->16).Reactive conformations 1^<*>, 8^<*>, 13, and 14 are postulated in agreement with X-ray evidence which also served for the structure determination of the product 9j.