Gravar-mail: Ethyl 23-benzyl-8,11,14-trioxa-23,28,29-triaza­penta­cyclo­[19.7.1.0(2,7).0(15,20).0(22,27)]nona­cosa-2,4,6,15(20),16,18,21,26-octa­ene-26-carboxyl­ate