4088-60-2Relevant articles and documents
Brown et al.
, p. 1750 (1972)
Gore et al.
, p. 1705,1708 (1975)
Czernecki et al.
, p. 127,128,129,131 (1977)
Deconvoluting the memory effect in Pd-catalyzed allylic alkylation: Effect of leaving group and added chloride
Fristrup, Peter,Jensen, Thomas,Hoppe, Jakob,Norrby, Per-Ola
, p. 5352 - 5360 (2006)
An analysis of product distributions in the Tsuji-Trost reaction indicates that several instances of reported "memory effects" can be attributed to slow interconversion of the initially formed syn- and anti- [Pd(η3-allyl)] complexes. Addition of chloride triggers a true memory effect, in which the allylic terminus originally bearing the leaving group has a higher reactivity. The latter effect, termed regioretention, can be rationalized by ionization from a palladium complex bearing a chloride ion, forming an unsymmetrically substituted [Pd(η3-allyl)] complex. DFT calculations verify that the position trans to the phosphine ligand is more reactive both in the initial ionization and in the subsequent nucleophilic attack.
Total Synthesis of Mycinolide IV and Path-Scouting for Aldgamycin N
Herlé, Bart,Sp?th, Georg,Schreyer, Lucas,Fürstner, Alois
supporting information, p. 7893 - 7899 (2021/03/03)
Proof-of-concept is provided that a large estate of 16-membered macrolide antibiotics can be reached by a “unified” approach. The key building block was formed on scale by an asymmetric vinylogous Mukaiyama aldol reaction; its alkene terminus was then converted either into the corresponding methyl ketone by Wacker oxidation or into a chain-extended aldehyde by catalyst-controlled branch-selective asymmetric hydroformylation. These transformations ultimately opened access to two structurally distinct series of macrolide targets. Notable late-stage maneuvers comprise a rare example of a ruthenium-catalyzed redox isomerization of an 1,3-enyne-5-ol into a 1,3-diene-5-one derivative, as well as the elaboration of a tertiary propargylic alcohol into an acyloin by trans-hydrostannation/Chan-Lam-type coupling. Moreover, this case study illustrates the underutilized possibility of forging complex macrolactone rings by transesterification under essentially neutral conditions.
SYNTHESIS OF (2S,3R,4R)-4,5-DIHYDROXYISOLEUCINE AND DERIVATIVES
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Page/Page column 23, (2019/10/19)
The invention relates to a method for the preparation of a 4,5-dihydroxyisoleucine derivative comprising the steps of asymmetric Claisen rearrangement of a Z-aminocrotyl-glycin ester and subsequent kinetic resolution of the product diastereomer mix by acylase, and subsequent Sharpless dihydroxylation of the resulting 2-amino-3-methylpent-4-enoicacid derivative.
