| abstract |
Compounds of formula (II) are simultaneously halogenated in the 5 position and hydroxylated in the 4 position under lactonization, the halolactone is converted into a hydroxylactone and then the hydroxy group into a leaving group, the leaving group is replaced with azide, the lactone amidated and then the azide converted to the amine group, in order to obtain compounds of formula (I). |