prov:value
| - R1 and R2, independently of one another, are hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkenyl or alkinyl group having 2 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms or a phenyl group which may also be substituted, each D, independently of one another, is NR3, O, PR3 or S, where R3 is an alkyl group having 1 to 6 carbon
|