Synthesis and geometrical configuration of luteoreticulin, a toxic nitro-containing metabolite of Streptomyces luteoreticuli arai

Abstract

2,4-Dimethyl-5-(p-nitrophenyl)penta-2,4-dienoic acid (2) and the related alcohol (3) and aldehyde (5) have been shown to have the (2E,4E)-configuration by a nuclear Overhauser effect experiment. The structure and stereo-chemistry [(6E,8E)] of luteoreticulin [3-methoxy-2,6,8-trimethyl-9-(p-nitrophenyl)nona-2,4,6,8-tetraen-5-olide](15) have been unequivocally confirmed by synthesis from the acid (2)via ring closure of the derived 9-aryl-2,6,8-trimethyl-3,5-dioxonona-6,8-dienoic acid (13).