Synthesis and reactivity of dimethoxy-functionalised Tröger’s base analogues

Tröger’s base analogues were prepared bearing methoxy groups in the 1,7-, 2,8-, 3,9- or 4,10-positions. These compounds were converted to their dihydroxy analogues in excellent yields upon treatment with boron tribromide and the 4,10-dihydroxy analogue could be prepared by directly from 4-hydroxyaniline. The synthetic utility of the dihydroxy-functionalised compounds as building blocks was demonstrated by the synthesis of a dialkoxy and a diester Tröger’s base analogue.