119803-96-2Relevant academic research and scientific papers
Total Syntheses of (+)-Thyrsiferol, (+)-Thyrsiferyl 23-Acetate, and (+)-Venustatriol
Hashimoto, Masaru,Kan, Toshiyuki,Nozaki, Koji,Yanagiya, Mitsutoshi,Shirahama, Harushia,Matsumoto, Takeshi
, p. 5088 - 5107 (2007/10/02)
The first total syntheses of (+)-thyrsiferol (1), (+)-thyrsiferyl 23-acetate (3), and (+)-venustatriol (5) have been accomplished in a stereoselective manner.An effective synthetic scheme to construct the BC ring system, which adopts a chair/twist-boat conformation, was first developed by means of a model study.This method involves stereoselective formation of the strained C ring by intramolecular attack of the C7-hydroxyl group at the C3-postion of the 2,3-epoxy alcohol, employing titanium tetraisopropoxide as an acidic activator.Based on the information accumulated in the model study and retrosynthetic considerations, the total syntheses of 1,3, and 5 were performed in the sequence of (1) construction of the BC ring system equipped with a C1-C6 carbon unit, (2) elongation of the C17-C24 carbon chain, (3) formation of a D ring through the stereoselective epoxidation of the 4-en-1-ol system and successive cyclization, and (4) construction of the A ring by bromonium ion induced cyclization of the 4-en-1-ol system.
EFFECTIVE DEPROTECTION OF 2-(TRIMETHYLSILYLETHOXY)METHYLATED ALCOHOLS (SEM ETHERS). SYNTHESIS OF THYRSIFERYL-23 ACETATE
Kan, Toshiyuki,Hashimoto, Masaru,Yanagiya, Mitsutoshi,Shirahama, Haruhisa
, p. 5417 - 5418 (2007/10/02)
New conditions for effective cleavage of SEM ethers were developed (TBAF/HMPA in the presence of MS 4A) and usefulness of this reaction was demonstrated by the synthesis of thyrsiferyl-23 acetate.
