Synthesis of the ABC-ring models of goniodomin A: preference for the unnatural configuration at C11 of the BC-ring in a non-macrocyclic model system

✍ Scribed by Takahiro Katagiri; Kenshu Fujiwara; Hidetoshi Kawai; Takanori Suzuki

• Publisher: Elsevier Science
• Year: 2008
• Tongue: French
• Weight: 186 KB
• Volume: 49
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2008.03.082

✦ Synopsis

To confirm the natural relative stereochemistry of the ABC-ring of goniodomin A (1), the corresponding three stereoisomeric compounds, (2R,5S,6S,7S,9S,11R,15S)-, (2R,5S,6S,7R,9R,11S,15R)-, and (2R,5S,6S,7R,9R,11R,15S)-isomers (2, 3, and 5, respectively), were stereoselectively synthesized using a Nozaki-Hiyama-Kishi reaction as a key step. It was also found that a (2R,5S,6S,7R,9R,11S,15S)-isomer (4), corresponding to the absolute configuration of 1 recently proposed by Sasaki, was not detected during the formation of 5 from a common ketodiol substrate under acid-catalyzed spiroacetalization conditions. This would be attributable to the absence of a macrocyclic framework.