Synthetic Studies toward C3‐C9 Segment of Soraphen A_1α

Abstract

The ring‐closure metathesis of the diene (2S,3R,4S)‐1‐(tert‐butyldiphenylsilyloxy)‐2,4‐dimethylhex‐5‐en‐3‐yl acrylate produced the dihydropyrone with the correct stereochemistry for Soraphen A_1α synthesis. The C2,C3 stereocenters were introduced by the addition of the (Z)‐crotyl‐n‐butylstannane to the β‐alkoxyaldehyde(S)‐3‐(benzyloxy)‐2‐methylpropanal in presence of TiCl₄ as a chelating catalyst to give the desired anti,syn homoallyic alcohol (2S,3R,4S)‐1‐(tert‐butyldiphenylsilyloxy)‐2,4‐dimethylhex‐5‐en‐3‐ol.

Keywords:

• Soraphen A_1α
• ring‐closure metathesis
• (Z)‐crotyl‐n‐butylstannane

Acknowledgments

Financial support for this work was provided by the National Institutes of Health (GM‐42641) and the Marquette University Graduate School. The author thanks Dr. William A. Donaldson for his encouragement.