Approach to the Core Structure of Signermycin B.

Area of Science:

• Organic Chemistry
• Natural Products Synthesis
• Stereoselective Synthesis

Background:

• Signermycin B is a natural tetramic acid featuring a unique cis-decalin moiety.
• The stereoselective synthesis of cis-decalin structures presents a significant challenge in organic chemistry.

Purpose of the Study:

• To develop a synthetic route to access the cis-decalin core of signermycin B.
• To investigate the utility of the anionic oxy-Cope rearrangement in constructing cis-decalin systems.

Main Methods:

• Intramolecular Diels-Alder reaction of a masked ortho-benzoquinone.
• Anionic oxy-Cope rearrangement of a tricyclic trienol intermediate.
• Enolate alkylation for substituent introduction.

Main Results:

• A tricyclic dienol was synthesized via an intramolecular Diels-Alder reaction.
• An anionic oxy-Cope rearrangement successfully generated a cis-decalinone intermediate.
• Enolate alkylation allowed for the introduction of the 4-ethyl substituent, albeit with formation of the 4-epi-isomer.

Conclusions:

• The anionic oxy-Cope rearrangement is an effective strategy for accessing the cis-decalin core of signermycin B.
• Stereocontrol during substituent introduction at the C4 position requires further optimization.