A flexible convergent enantioselective totalsynthesis of a rigid lipoxin B4 analog incorporating a 6, 11‐methylene bridge has been developed. C1–C12 aldehyde and C13–C20 ketophosphonate underwent highly efficient key Horner olefination. A final six‐step sequence delivered the target compound displaying all stereogenic centers with standard lipoxin B4 configurations.
A novel one-pot procedure for the stereoselectivesynthesis of α-hydroxy estersfrom ortho esters was developed. Key steps were multi-heteroatom Cope rearrangements of O-acylated N-hydroxy-l-tert-leucinol-derived oxazoline N-oxides leading to α-acyloxy oxazolines and, after methanolysis, to the target molecules in 67−80% yield and 94−98% ee.
Enantioselective syntheses of (+)- and (−)-Phaseolinic acid
作者:Peter A. Jacobi、Prudencio Herradura
DOI:10.1016/0040-4039(96)01941-7
日期:1996.11
(+)- and (−)-Phaseolinicacid (1) have been prepared in an enantioselective fashion from acetylenic acid 26 (or ent-26) by a three step sequence involving lactonization, epimerization at C3, and oxidative cleavage. 26 was obtained as a single enantiomer using a Nicholas-Schreiber reaction.
A new process for the enantioselective synthesis of chiral α-aryloxy- and α-hydroxy acids
作者:E.J. Corey、John O. Link
DOI:10.1016/s0040-4039(00)92655-8
日期:1992.6
Chiral trichloromethyl carbinols 3, readily available by catalytic enantioselective reduction of trichloromethyl ketones, are converted with inversion of configuration into chiral α-aryloxy and α-hydroxy carboxylic acid derivatives.