| abstract |
The invention relates to a process for the preparation of substantially pure enantiomers of (3-amino-3-carboxy-propyl)-alkyl phosphinic acid derivatives by asymmetric synthesis and to herbicidally and bioregulatory active pyrazine derivatives of the formula <IMAGE> in which R<1> denotes alkyl, R<2> denotes hydrogen, alkyl or haloalkyl, R<3> denotes hydrogen or alkyl, R<4> denotes hydrogen or alkyl, R<5> denotes hydrogen or alkyl, and R<6> denotes alkyl or benzyl, which are used in this process.t |