Abstract:
Tetrabromo-2-benzoquinone reacts with cyclopentenyl ) piperidine and 1-(1-cyclohexenyl ) piperidine to give the open (1:1) adduct (la,b) or (I'a,b), whereas it reacts with I-cyclopentenyl ) morpholine to give the open (1:1) addition product (Ic or I 'c) together with the cyclic (l : l ) addition product ( Ila or I l 'a). However, it reacts with 4-(1-cyclohexenyl ) morphol ine to give the cyclic (1:1) addition product ( 1 1b or I l b)
