Synthesis of Cyclododecane-r-1,c-5,c-9-triyl Tris(2,3-dihydroxybenzoate), a carbocyclic analogue of enterochelin

Abstract

Reaction of cyclododecane-r-1,c-5,c-9-triol with 2,3-dimethoxybenzoyl chloride in pyridine gave cyclododecane-r-1,c-5,c-9-triyl tris(2,3- dimethoxybenzoate), which upon treatment with 3 mol of boron tribromide at low temperature gave 83% yield of cyclododecane-r-1,c-5,c-9-triyl tris(2-hydroxy-3-methoxybenzoate). When 6.5 mol of boron tribromide was used under similar conditions cyclo-dodecane-r-1,c-5,c-9-triyl tris(2,3-dihydroxybenzoate) was obtained in 77% yield. Some model reactions of isopropyl 2,3-dimethoxybenzoate with boron tribromide are described.