10.1021/acs.orglett.7b01513.s001
Younes Fegheh-Hassanpour
Younes
Fegheh-Hassanpour
Tanzeel Arif
Tanzeel
Arif
Herman O. Sintim
Herman O.
Sintim
Hamad H. Al Mamari
Hamad H.
Al Mamari
David M. Hodgson
David M.
Hodgson
Synthesis of (−)-6,7-Dideoxysqualestatin H5
by Carbonyl Ylide Cycloaddition–Rearrangement and Cross-electrophile
Coupling
American Chemical Society
2017
hydrazone
diazo functionality
Csp
facilitation
co-generation
cross-electrophile
β- hydroxy -α-ketoester motif
Rh
tartrate acetonide enolate
Ylide
Cross-electrophile
alkylation
synthesis
stereoretentive
oxidation
diastereoselective n
tricarboxylate core
ylide
formation
dideoxysqualestatin
Dideoxysqualestatin
Key features
Ni-catalyzed
carbonyl
entry
cyclic
Carbonyl
ozonolysi
side chain
Synthesi
Cycloaddition
2017-06-19 23:03:42
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Synthesis_of_-6_7-Dideoxysqualestatin_H5_by_Carbonyl_Ylide_Cycloaddition_Rearrangement_and_Cross-electrophile_Coupling/5119996
An asymmetric synthesis
of (−)-6,7-dideoxysqualestatin H5
is reported. Key features of the synthesis include the following:
(1) highly diastereoselective <i>n</i>-alkylation of a tartrate
acetonide enolate and subsequent oxidation–hydrolysis to provide
an asymmetric entry to a β-hydroxy-α-ketoester motif;
(2) facilitation of Rh(II)-catalyzed cyclic carbonyl ylide formation–cycloaddition
by co-generation of keto and diazo functionality through ozonolysis
of an unsaturated hydrazone; and (3) stereoretentive Ni-catalyzed
Csp<sup>3</sup>–Csp<sup>2</sup> cross-electrophile coupling
between tricarboxylate core and unsaturated side chain to complete
the natural product.