Selective cleavage of bridged-ring cyclopropyl ketones

✍ Scribed by Samuel K. Attah-Poku; Sandra K. Alward; Alex G. Fallis

• Book ID: 104216988
• Publisher: Elsevier Science
• Year: 1983
• Tongue: French
• Weight: 190 KB
• Volume: 24
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)81497-5

✦ Synopsis

Summatty: Reductive ring opening of the tetracyclic cyclopropyl ketones l_ to 3 is described and affords selective entry to the tricyclo[4.4.01y605'g ldecane (sinularene) and to the tricyclo[5.4.01'7.06'10 lundecene (longifolene) skeletons. Controlled cleavage of cyclopropane intermediates provides a useful method for the total synthesis of multicyclic natural products and has been successfully employed in the stereocontrolled synthesis of (+)hinesol, (')epihinesol,' (-)-acorenone B and (+)-cl-chamigrene. ' We are developing a general, intramolecular Diels-Alder approach to the tricyclic skeletons represented in nature by sinularene, longifolene and sativene. 3 As illustrated, this strategy requires, after construction of the appropriate tetracyclic precursor, selective cyclopropane bond cleavage (a, b, or c) to afford the desired tricylic ring systems. Reductive opening of the conjugated cyclopropyl ketones 1,to 3_with controlled rupture of bonds "a" or "b" is described.