80267-24-9Relevant articles and documents
Total Syntheses of Scaparvins B, C, and D Enabled by a Key C-H Functionalization
Ye, Qinda,Qu, Pei,Snyder, Scott A.
supporting information, p. 18428 - 18431 (2018/01/11)
The clerodane diterpene family possesses an impressive range of bioactivities and high synthetic challenge due to their unique amalgamation of rings, stereocenters, and oxygenation. Herein, we disclose the first total syntheses of three members, scaparvin
TOTAL SYNTHESIS OF THE INSECT ANTIFEEDANT AJUGARIN I AND DEGRADATION STUDIES OF RELATED CLERODANE DITERPENES
Jones, Philip S.,Ley, Steven V.,Simpkins, Nigel S.,Whittle, Alan J.
, p. 6519 - 6534 (2007/10/02)
The first total synthesis of the diterpene clerodane insect antifeedant ajugarin I (1) has been achieved.The key step of the synthesis discloses the use of the 1,3-dithiolane unit to stereochemically direct the conjugate addition of a but-3-enyl cuprate to set in place the C-10 sp3 carbon centre.The trans-fused ring geometry was obtained by conjugate addition of a vinyl cuprate to an enone and regio and stereoselectively trapping the resulting enolate with formaldehyde.Introduction of the necessary butenolide side chain was achieved by conjugate addition of a sulphone stabilised anion to ethyl-4-(t-butyldimethylsilyloxy)but-2-ynoate followed by work-up with fluoride.Final hydroxyl directed epoxidation was not specific giving both the natural product ajugarin I and its 4-epi isomer.Chemical modification of the insect antifeedant clerodin hemiacetal afforded a series of side chain modified structures for biological evaluation.
