An unprecedented gedunin rearrangement reaction converts a methyl group into the methylene group of a cyclopropyl ring

作者：Okhale Samuel E; Decatur John; Itagaki Yasuhiro; Amupitan Joseph O; Ndukwe George I; Ellestad George; Okogun Joseph I^*

来源：Tetrahedron, 2014, 70(37): 6656-6662.

DOI：10.1016/j.tet.2014.06.067

• Gedunin
• Acid-catalysed rearrangement reaction
• Intramolecular cyclopropanation
• Chemosystematics
• Phylogenetic history

Herein we describe an unprecedented formation of a cyclopropane ring through the conversion of a methyl group that was not functionalized for the purpose. In a one-step reaction, 7-deacetoxy-7 alpha-hydroxygedunin (4) afforded two new gedunin derivatives, namely 7-deacetoxy-13,14,18-cyclopropyl-7 alpha,15 beta, 17 xi-trihydroxy-gedu-16-oic acid (7) and 7-deacetoxy-9,11-en-7 alpha,15 beta-dihydroxygedunin (8) along with the known 7-deacetoxy-7,9-diene-15 beta-hydroxygedunin (5).

• 出版日期2014-9-16