Photochemical and Thermal [2 + 2] Cycloaddition to Generate the Bicyclo[3.2.0]­hept­ane Core of Bielschowskysin. Issue 20 (7th June 2013)

• Record Type: Journal Article
• Authors: Farcet, Jean‐Baptiste; Himmelbauer, Martin; Mulzer, Johann
• Is Part Of: European journal of organic chemistry. Issue 20(2013)
• Page Start: 4379
• Page End: 4398
• Publication Date: 2013-06-07
• Subjects: Total synthesis -- Natural products -- Terpenoids -- Photochemistry -- Oxidation; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201300382
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: A bicyclic core fragment of the marine diterpenoid bielschowskysin has been synthesized. First, a large library of precursors for a photochemical [2 + 2] cycloaddition was prepared and tested, but with limited success. In the end, a thermal [2 + 2] cycloaddition followed by appropriate regio‐ and stereocontrolled functionalization efficiently gave access to the desired bicyclo[3.2.0]heptane core. An optimized route to this remarkable molecular structure is presented. Abstract : Various photocycloaddition precursors have been designed to study both biomimetic and non‐biomimetic [2 + 2] cycloadditions to form the bicyclo[3.2.0]heptane core of the marine diterpenoid bielschowskysin. Additionally, an optimized thermal approach to aldehyde (–)‐55 is described.