ABSTRACT
Two approaches to stereoselective synthesis of steroid 5Z,9Z-dienoic acids were developed, the first one being based on the cross-cyclomagnesiation of 2-(hepta-5,6-dien-1-yloxy)tetrahydro-2H-pyran and 1,2-diene cholesterol derivatives on treatment with EtMgBr catalyzed by Cp2TiCl2, while the other involving the synthesis of esters of hydroxy steroids with (5Z,9Z)-tetradeca-5,9-dienedioic acid, prepared in two steps using homo-cyclomagnesiation of 2-(hepta-5,6-dien-1-yloxy)tetrahydro-2H-pyran as the key step. High inhibitory activity of the synthesized acids against human topoisomerase I (hTop1) was found.
Subject(s)
DNA Topoisomerases, Type I/chemistry , Steroids , Topoisomerase I Inhibitors , Humans , Steroids/chemical synthesis , Steroids/chemistry , Topoisomerase I Inhibitors/chemical synthesis , Topoisomerase I Inhibitors/chemistryABSTRACT
(5Z,9Z)-11-Phenylundeca-5,9-dienoic acid was stereoselectively synthesized, based on original cross-cyclomagnesiation of 2-(hepta-5,6-dien-1-yloxy)tetrahydro-2H-pyran and buta-2,3-dien-1-ylbenzene with EtMgBr in the presence of the Cp2TiCl2 catalyst giving 2,5-dialkylydenemagnesacyclopentane in 86% yield. The acid hydrolysis of the product and Jones oxidation of the resulting 2-{[(5Z,9Z)-11-phenylundeca-5,9-dien-1-yl]oxy}tetrahydro-2Ð-pyran afforded (5Z,9Z)-11-phenylundeca-5,9-dienoic acid in an overall yield of 75%. A high inhibitory activity of the synthesized acid with respect to human topoisomerase I (hTop1) and II (hTop2α) was detected. Resorting to the data of molecular docking, a mechanism of inhibition was proposed.
