Synthesis of (±)-5,6,7-trinor-4,8-inter-m-phenylene PGI2
A stable and potent analog of prostacyclin, the titled compound, and its derivative were synthesized from readily available 1,4-dibromocyclopentene via 5-(4-tetrahydropyranyloxybutyl)cyclopenta[b]benzofuran 7.
Synthesis of 5,6,7-trinor-4,8-inter-m-phenylene PGI2 and Beraprost
We have disclosed a new class of stable PGI2 analogue, 5,6,7-trinor- 4,8-inter-m-phenylene PGI2 which has a phenyl ether moiety instead of enol- ether skeleton in PGI2. The m-phenylene PGI2 and its derivative (Betaprost) were synthesized via dihydrocyclopenta[b]benzofuran derivatives as key intermediates by ortho-selective metal-halogen exchange reaction with Grignard reagents and subsequent copper-catalyzed cyclization. The ω-side chains were introduced by stereoselective epoxide formation or Prins reaction.