Determination of the Relative and Absolute Configuration of the Dimethylmyristoyl Side Chain of Pneumocandin B<sub>0</sub> by Asymmetric Synthesis
作者:William R. Leonard,、Kevin M. Belyk、Dean R. Bender、David A. Conlon、David L. Hughes、Paul J. Reider
DOI:10.1021/ol0261940
日期:2002.11.1
[reaction: see text] The relative and absoluteconfiguration of the pneumocandin B(0) sidechain has been established as (10R,12S)-dimethylmyristoyl by the stereocontrolled synthesis of both antipodes of the sidechain acid and their comparison to a sample derived from the natural product.
Total syntheses of jaspamide (jasplakinolide) and geodiamolide A and B - 1. Stereoselective synthesis of (2,4,6,8)-8-hydroxy-2,4,6-trimethyl-4-nonenoicic acid1
作者:Ulrich Schmidt、Wolfgang Siegel、Klaus Mundinger
DOI:10.1016/s0040-4039(00)80273-7
日期:1988.1
The chiral aldehyde 7 was prepared by diastereoselective alkylation, subsequent 1,2- addition of isopropenylmagnesium bromide gave rise to a mixture (68:32) of the allylic alcohols 8 and 10 which was separated by recycling MPLC. Claisen rearrangement of the propionates of these alcohols under control of the enolate geometry finally yielded hydroxynonenoic acid 12b.
An asymmetricsynthesis of the spirocyclic core of pinnaicacid, a cPLA2 inhibitor, is described. A key transformation in the sequence involves an asymmetric Michael-initiated ring closure.