Synthesis of C1-C5 and C7-C13 fragments of (-)-Ebelactone A

Author(s)

Caroline da Costa Silva Gonçalves

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2005-07-29

Examining board members

Luiz Carlos Dias; Helio Alexandre Stefani; José Augusto Rosário Rodrigues

• Advisor: Luiz Carlos Dias

Abstract

The ebelactones A and B are enzime inhibitors isolated by Umezawa and cowokers in 1980, from a culture strain of soil actinomycetes (MG7-G1 related to Streptomyces aburaviensis). This work describes the synthesis of C1-C5 and C7-C13 fragments of (-)-ebelactone A. The C1-C5 and C7-C13 fragments of (-)-ebelactone A were prepared from a common intermediate, alcohol 72. Notable features of this approach include an anti-aldol reation and a diastereoselective hydroboration. Fragment C1-C5 was prepared in 6 steps and 32% overall yield from N-propionyloxazolidinone. A second version of C1-C5 fragment, corresponding to the b-lactone ring, was prepared in 13 steps and 2.8% overall yield. Fragment C7-C13 was prepared in 14 steps and 5.5% overall yield from N-propionyloxazolidinone. Notable features include a Horner-Wadsworth-Emmons, a diastereoselective epoxidation of an allylic alcohol with m-CPBA followed by epoxide opening with Me2CuLi2. (AU)