Synthesis of Two Alnustone-Like Natural Diarylheptanoids via 4 + 3 Strategy

Abstract

The first total synthesis of (4E,6E)-1,7-bis(3,4-dihydroxyphenyl)-hepta-4,6-dien-3-one and an alternative synthesis of (4E,6E)-1,7-bis(4-hydroxyphenyl)-hepta-4,6-dien-3-one, two natural diarylheptanoids, mainly based on Claisen–Schmidt condensation were described. The crucial steps of the syntheses were the condensation of OH-protected 4-aryl-2-butanones with OH-protected 3-aryl-acrylaldehydes by the in situ enamination and then deprotection of OH groups to give the corresponding natural diarylheptanoids.

Keywords:

• 1,7-Bis(3,4-dihydroxyphenyl)-hepta-4,6-dien-3-one
• 1,7-bis(4-hydroxyphenyl)-hepta-4,6-dien-3-one
• Claisen–Schmidt condensation
• diarylheptanoid
• in situ enamination
• synthesis

ACKNOWLEDGMENTS

We thank the Scientific and Technological Research Council of Turkey (TBAG-105T168) and Atatürk University for financial support of this work, Dr. Ebru Mete for elemental analysis, and Bilal Altundas for linguistic corrections.

Notes

Dedicated to Professor Metin Balcı on the occasion of his 60th birthday.