N,N,N',N',N'',N''-hexamethylphosphoric triamide; n-butyllithium in tetrahydrofuran
T=-78 - 20°C; one-pot reaction with aldehydes and ketones giving stereoselectively E-1,3-dienes, also with 3-diphenylphosphoryl-1-butene; Product distributionMechanism;