19464-85-8Relevant articles and documents
Stereoselective total synthesis of (+)-nephrosteranic acid and (+)-roccellaric acid through asymmetric dihydroxylation and Johnson-Claisen rearrangement
Fernandes, Rodney A.,Chowdhury, Asim K.
, p. 1106 - 1112 (2011)
An efficient stereoselective total synthesis of (+)-nephrosteranic acid and (+)-roccellaric acid is presented. The synthetic strategy features the regioselective asymmetric dihydroxylation of the γ,δ-olefinic bond of a α,β,γ,δ-unsaturated ester and the Johnson-Claisen rearrangement as the key steps. The synthesis is achieved in 10 steps and 6.8% (nephrosteranic acid) and 7.6% (roccellaric acid) overall yield.
A protecting-group-free synthesis of (+)-nephrosteranic, (+)-protolichesterinic, (+)-nephrosterinic, (+)-phaseolinic, (+)-rocellaric acids and (+)-methylenolactocin
Nallasivam, Jothi L.,Fernandes, Rodney A.
, p. 708 - 716 (2017/01/25)
A collective synthesis of a γ-butyrolactone class of paraconic acids such as (+)-methylenolactocin, (+)-phaseolinic acid, (+)-nephrosteranic acid, (+)-nephrosterinic acid, (+)-rocellaric acid and (+)-protolichesterinic acid is described. The strategy adopted is protecting-group-free based on efficient Pd-catalyzed Suzuki-Miyaura coupling and Ru-catalyzed Sharpless oxidation to construct the core β-CO2H-γ-butyrolactone unit to accomplish the synthesis of various paraconic acids.
Enantioselective butenolide preparation for straightforward asymmetric syntheses of γ-lactones - Paraconic acids, avenaciolide, and hydroxylated eleutherol
Braukmueller, Stefan,Brueckner, Reinhard
, p. 2110 - 2118 (2007/10/03)
The naturally occurring γ-lactones (+)-methylenolactocin (13) and its enantiomer, (+)-protolichesterinic acid (14) and its enantiomer, (+)-rocellaric acid (15), and the methylene bis(γ-lactone) (-)-avenaciolide (16) were synthesized with 95-98 % ees in very few steps. Enantiocontrol was imposed by the asymmetric dihydroxylation of trans-configured β,γ-unsaturated carboxylic esters (namely compounds 1i, 1j, and 1n) with AD mix-α [for the levorotatory target structures, except for (-)-avenaciolide] or AD mix-β [for the dextrorotatory target structures plus (-)-avenaciolide]. β,γ-Unsaturated carboxylic ester 1e required increased amounts of the oxidant and auxiliary to produce the hydroxy lactone R,R-3e, a precursor of the naphtho-γ-lactone (+)-9-hydroxyeleutherol (12; 96 % ee). Wiley-VCH Verlag GmbH & Co. KGaA, 2006.