Short Diastereoselective Synthesis of the C1–C13 (AB Spiroacetal) and C17–C28 Fragments (CD Spiroacetal) of Spongistatin 1 and 2 through Double Chain-Elongation Reactions

✍ Scribed by Dr. Christopher L. Flowers; Prof. Dr. Pierre Vogel

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 370 KB
• Volume: 16
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.201002204

✦ Synopsis

Abstract

A unique and practical synthetic sequence for rapid access to polyketides and to further the spiroacetals derived from them, which utilizes a bidirectional Hosomi–Sakurai allylation approach around key allylsilanes in the synthesis of the AB and CD ring systems of spongistatin 1 and 2, is reported. The synthesis of the AB spiroacetal 9 requires 13 steps, with a longest linear sequence of seven steps in an overall yield of 27 %. The synthesis of the CD spiroacetal 13 requires 15 steps, with a longest linear sequence of 11 steps in an overall yield of 30 %. Both syntheses start from but‐3‐enol.