Studies On Synthesis Of Capparisine B And Its Derivatives

In this paper, Nonsteroidal Anti-inflammatory drugs and pharmacological activities of Capparis spinosa had been reviewed. Total synthesis of Capparisine B was described. We designed and synthesized five Capparisine B derivatives.Each natural product has its own biosynthetic pathway. Amino acid is thought to be involved in the biosynthesis of alkaloid. In the present research, we try to mimic the alkaloid biosynthetic pathway and use L-alanine as starting material to synthesis Capparisine B firstly.Starting from L-alanine, the facile and efficient total synthesis of Capparisine B was achieved in six steps with a 17.0% overall yield. The synthetic rount involves Clauson-Kaas reaction, Vilsmeier reaction and transesterification. Significantly, the synthetic scheme proposed in this work has the characteristics of mild reaction conditions, inexpensive reagents and simple operation.According to theory of bioisostere, we designed and synthesized five derivatives of Capparisine B. Starting from pyrrole, the 3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carba-ldehyde was synthesized by Vilsmeier reaction, Williamson reaction and reduction. And then (E)-6-styryl-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine, (E)-6-(4-fluorostyryl)-3,4-dihydro-1 H-pyrrolo[2,1-c][1,4]oxazine, (Z)-7-(4-fluorostyryl)-3,4-dihydro-1H-pyrrolo[1,2-c][1,3] oxazine, (E)-6-(4-chlorostyryl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine and (Z)-7-(4-chlorostyryl)-3,4-dihydro-1H-pyrrolo[1,2-c][1,3]oxazine was synthesized by Wittig reaction.Sixteen compounds were synthesized in the paper, among which ten compounds were first prepared. All the new structures were confirmed by NMR, MS and IR analysis.