A Practical Building Block for the Synthesis of Discodermolide
作者:Olivier Loiseleur、Guido Koch、Trixie Wagner
DOI:10.1021/op049950l
日期:2004.7.1
A new highly diastereoselective and practical route to the lactone 6a which is used as a key building block for the total synthesis of the microtubule-stabilizing anticancer agent discodermolide is reported. This exploits the chiral auxiliary (4R)4-isopropyl-5,5-diphenyloxazolidin-2-one (7) which conveys crystallinity to the synthetic intermediates throughout the entire process. Purifications can thus be performed by recrystallization, avoiding chromatography to afford the final product in high enantiomeric purity. The overall efficiency is augmented by the facile recovery of the auxiliary by precipitation at the end of the sequence.
COMBINATORIAL POLYKETIDE LIBRARIES PRODUCED USING A MODULAR PKS GENE CLUSTER AS SCAFFOLD
申请人:Kosan Biosciences
公开号:EP0979286B1
公开(公告)日:2014-01-29
US7652031B2
申请人:——
公开号:US7652031B2
公开(公告)日:2010-01-26
Regulated-Stereoselective Construction of Thirteen Stereogenic Centers Necessary for the Frame of (+)-Discodermolide, Based on Iterative Lewis Acid-Promoted Aldol Reactions
and diastereoselective (BF(3).OEt(2) and TiCl(4)) aldol reactions with the silylketene acetal, coupled with diastereoselective radical debrominations (Bu(3)SnH, Et(3)B, with or without MgBr(2)), were used iteratively. This aldol reaction strategy for the construction of the polypropionate frame dramatically shortened the steps needed for the construction of the final segments.
(+)-11,11′-Di-O-methylelaiophylidene – preparation from elaiophylin and total synthesis from (R)-3-hydroxybutyrate and (S)-malate
作者:Dieter Seebach、Hak-Fun Chow、Richard F. W. Jackson、Marius A. Sutter、Suvit Thaisrivongs、Jürg Zimmermann
DOI:10.1002/jlac.198619860714
日期:1986.7.14
methanol, with replacement of two lactol OH-groups by OCH3 (C-11 and C-11′). The di-O-methylelaiophylidene (8a), a C2-symmetrical macrodiolide with 2 × 11 stereogenic units, was synthesised from (R)-3-hydroxy-butanoate (from the biopolymer PHB) and (S)-malic ester, using diastereoselective steps for the generation of the other stereogenic units. The key intermediates (Scheme 2) are the macrocyclic dialdehyde