ChemInform Abstract: A Formal Total Synthesis of (.+-.)-Homogynolide-B.

✍ Scribed by Adusumilli Srikrishna; Sankuratri Nagaraju; Somepalli Venkateswarlu; Uma S. Hiremath; T. Jagadeeswar Reddy; Paloth Venugopalan

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 37 KB
• Volume: 30
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199946176

✦ Synopsis

A Formal Total Synthesis of (±)-Homogynolide-B.

-The key intermediate keto ketals (III) and (IV), derived from ester (I), are further converted in a separate way to the target spirolactone (XIII), the Greene's precursor of homogynolide-B. The 5-exo-dig radical cyclization of the bromo acetal (X) followed by hydrolysis and oxidation give the desired product (XIII). The similar treatment of diastereomer (IV) results in a mixture of diastereomers (XIII) and (XIV), due to the partial epimerization of the secondary methyl group during the hydrolysis of the ketal moiety. Complete epimerization of the mixture of spirolactones (XIII) and (XIV) is achieved by treatment with