Synthesis of (R)- and (S)-4-Hydroxy-2-cyclopenten-1-ones: Total Synthesis of Entecavir, Abacavir, and Carbovir.

Area of Science:

• Organic Synthesis
• Green Chemistry
• Asymmetric Synthesis

Background:

• Entecavir, abacavir, and carbovir are crucial antiviral medications.
• Efficient and enantioselective synthesis of chiral synthons is vital for pharmaceutical production.
• Developing greener industrial processes is a key objective in modern chemistry.

Purpose of the Study:

• To develop a novel synthetic procedure for chiral synthons (R)-1b and (S)-1b.
• To achieve the asymmetric total synthesis of entecavir, abacavir, and carbovir.
• To explore the potential of a lipase-based green process for industrial applications.

Main Methods:

• Lipase-catalyzed kinetic resolution for chiral synthon production.
• Asymmetric synthesis of entecavir via Michael addition-elimination.
• Asymmetric synthesis of abacavir and carbovir using photoradical addition.
• 1,3-diaza Cope rearrangement for novel synthetic strategies.

Main Results:

• Successful development of a new synthetic route for (R)-1b and (S)-1b with high enantiomeric purity.
• Completion of the asymmetric total synthesis of entecavir, abacavir, and carbovir.
• Demonstration of a green, lipase-based procedure with industrial production potential.
• Discovery of a novel 1,3-diaza Cope rearrangement.

Conclusions:

• The developed lipase-based procedure is a promising green route for producing chiral synthons.
• The synthetic strategies enable efficient access to important antiviral drugs.
• This research lays the groundwork for future industrial process development and synthetic innovation.