Aprotic conjugate addition of allyllithium reagents bearing polar groups to cyclic enones. 1. 3-Alkylallyl systems

Enantioselective synthesis of tatanans A–C and reinvestigation of their glucokinase-activating properties

“…However, various attempts to remove the vinylic phosphoramide substituent proved to be prohibitively inefficient, prompting us to seek a more practical alternative. Addition of the lithiated (R)-tert-butyl (E)-2-butenyl sulfoxide 24 21 occurred with high diastereoselectivity, delivering ester 22 as a single diastereomer in 50% yield after in situ methylation of the transient ester enolate 25 . Diastereoisomeric products resulting from α-alkylation of the sulf-oxide accounted for the remainder of the mass balance.…”

Synthesis of Sulfoxides by the Hydrogen Peroxide Induced Oxidation of Sulfides Catalyzed by Iron Tetrakis(pentafluorophenyl)porphyrin: Scope and Chemoselectivity.

“…The identity of the isolated products (sulfoxides, sulfones or disulfoxides) was established by comparing their spectral and physical properties with those of commercial samples (methyl phenyl sulfoxide, chloromethyl phenyl sulfoxide, diphenyl sulfoxide, allyl phenyl sulfoxide, phenyl vinyl sulfoxide, dibutyl sulfoxide, bis-(2-hydroxyethyl) sulfoxide, allyl phenyl sulfone, phenyl vinyl sulfone and bis-(2-hydroxyethyl) sulfone) or with those reported in the literature: 4-cyanophenyl methyl sulfoxide, 8 4-dimethylaminophenyl methyl sulfoxide, 9 4-hydroxymethylphenyl methyl sulfoxide, 10 tbutyl phenyl sulfoxide, 11 2-phenylsulfinylethanol, 12 1-phenyl-2-phenylsulfinylethanol, 13 trifluoromethyl phenyl sulfoxide, 14 3-methyl-but-2-enyl phenyl sulfoxide, 15 phenyl styryl sulfoxide, 16 butyl t-butyl sulfoxide, 17 di-sec-butyl solfoxide, 18 bis-(3-methyl-but-2-enyl) sulfoxide, 7 4-oxo-1,4-thioxane, 19 1-oxo-1,3-dithiane, 20 1,3-dioxo-1,3-dithiane, 21 1-oxo-1,3-dithiolane, 22 1,3-dioxo-1,3-dithiolane, 23 2-(phenylsulfonyl)ethanol, 24 1-phenyl-2-phenylsulfonylethanol, 25 3-methyl-2-butenyl phenyl sulfone, 26 phenyl styryl sulfone 27 and bis-(3-methyl-but-2-enyl) sulfone 28 . S4…”

Application of chiral sulfoxides in asymmetric synthesis

“…After chromatographic separation of the mixture of hydroxyl sulfoxides resulting from the reaction of lithium anion derived from optically pure sulfoxide 22 and undecanal, disparlure 25, was obtained from the major diastereomer through a sequence involving sulfoxide reduction and base promoted cyclization of the sulfonium salt derived from the thioether (Figure 11). The regio-and Stereochemical course of the reaction between ambident sulfinyl allyl anions and cyclic enones has been deeply studied by Binns et al [32][33][34] while its application to asymmetric synthesis of natural products was mainly due to Hua et al 35,36 Total synthesis of (+)-hirsutene 32 employed two crucial reactions i.e. i.…”