84363-80-4Relevant academic research and scientific papers
Stereocontrol in the Nucleophilic Epoxidation of α-(1-Hydroxyalkyl)-α,β-Unsaturated Sulfones
Jackson, Richard F. W.,Standen, Stephen P.,Clegg, William,McCamley, Andrew
, p. 141 - 148 (2007/10/02)
Epoxidation of β-unsaturated-α-(1-hydroxyalkyl)-α,β-unsaturated sulfones 1 with lithium tert-butyl peroxide proceeds with high diastereoselectivity to give the syn epoxides 10.Epoxidation of the triisopropylsilyl ethers 7, however, leads to the anti epoxides 13 with moderate to good selectivity.In contrast to this, epoxidation of (E)-α-(1-hydroxyalkyl)-β-phenyl-α,β-unsaturated sulfones 2 proceeds with high diastereoselectivity to give the anti epoxides 15.Epoxidation of the corresponding triisopropylsilyl ethers 9 leads to a reversal in diastereofacial selectivity, giving the syn epoxides 16 with moderate selectivity.The sense of diastereoselectivity has been determined by X-ray crystal-structure analyses of compounds 10c, 13a, 13b and 16a and chemical correlation.Use of potassium tert-butyl peroxide as the epoxidising agent for all these epoxidation reactions results in very similar levels of diastereoselectivity to those observed using lithium tert-butyl peroxide.A rationalisation for these results, based on the influence of 1,2- and 1,3-allylic strain, is proposed.
Synthesis and Reactions of α-Methylene-β-keto Sulfones
Weichert, Andreas,Hoffmann, H. Martin R.
, p. 4098 - 4112 (2007/10/02)
Modified Jones oxidation of 2-(benzenesulfonyl)-2-alken-1-ols and rapid nonnucleophilic workup below 0 deg C yields a variety of α-methylene-β-keto sulfones 4, including crystalline parent 4a and also e-h, which can be stored at -20 deg C without change.I
DIMERIZATION OF (E)-2-BENZENESULFONYL-1,3-ALKADIENES. THE BENZENESULFONYL GROUP EXERTS ACYCLIC STEREOCONTROL
Hoffmann, H. Martin R.,Weichert, Andreas,Slawin, Alexandra M. Z.,Williams, D. J.
, p. 5591 - 5602 (2007/10/02)
Mild dehydration of 2-benzenesulfonyl allylic alcohols 8 afforded a series of (E)-2-benzenesulfonyl-1,3-alkadienes 1 which dimerized to functionalized vinylcyclohexenes 3 in regio- and stereodefined manner.The configuration at C-3 in 3e was determined by
PREPARATION AND NUCLEOPHILIC SUBSTITUTION OF (E)-1-BROMO-2-PHENYLSULFONYL-2-ALKENES AND 3-ACETOXY-2-PHENYLSULFONYL-1-ALKENES
Auvray, P.,Knochel, P.,Normant, J. F.
, p. 6095 - 6106 (2007/10/02)
Vinylphenylsulfone reacts with aldehydes to yield sulfonylated secondary allylic alcohols wich are converted to either primary allylic bromides, or secondary allylic acetates.Both react highly regioselectively with lithium cyanocuprates, or enolates.
AN EASY SYNTHESIS OF THE 2-PHENYLSULFONYL-SUBSTITUTED ALLYLIC BROMIDES AND ACETATES AND THEIR REACTIVITY TOWARDS NUCLEOPHILES
Auvray, P.,Knochel, P.,Normant, J. F.
, p. 5095 - 5098 (2007/10/02)
The reaction of phenyl vinyl sulfone with various aldehydes in the presence of a catalytic amount of DABCO furnishes in good yields the corresponding 2-phenylsulfonyl-substituted alcohols 5a-5e which can be easily converted into their acetates 2a-2b or into their allylically rearranged bromides 3a-3d.These reagents, in turn, react with nucleophiles (ketone enolates and cuprates) with an allylic rearrangement (SN2' mechanism) to give the functionalized unsaturated sulfones 6a-g and 7a-g.A palladium catalyzed reaction allows a stereo-controlled transformation of the sulfone 6b into the (Z,Z) skipped 1,4-diene 8.
1-BENZENESULFONYL-2-TRIMETHYLSILYLETHANE AND 1-BENZENESULFONYL-1-CHLORO-2-TRIMETHYLSILYLETHANE; EFFICIENT REAGENTS FOR SULFONYL-α-VINYLATION
Hsiao, C-N.,Shechter, H.
, p. 3455 - 3458 (2007/10/02)
1-Benzenesulfonyl-2-trimethylsilylethane and 1-benzenesulfonyl-1-chloro-2-trimethylsilylethane are convertable to 1-benzenesulfonyl-1-chloro-1-substituted-2-trimethylsilylethanes which undergo elimination by fluoride ion to give phenyl α-substituted-vinyl
