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Alkylation deconjugative

Kende and Toder have reported that deconjugative alkylations of (Z)-2-alkenoates give the corresponding ( )-3-enoate derivatives, while ( )-2-alkenoates give (Z)-3-enoate isomers unless the 4-substituent is larger than methyl. They suggested that the stereoselectivity of these reactions is probably determined by the conformation of e a, -unsaturated ester that undergoes deprotonation at C-4. [Pg.51]

Disubstituted P,Y-unsaturated nitriles. After deconjugative alkylation of enal A,Ai-dimethylhydrazones, MMPP oxidation (MeOH, 0°) furnishes the nitriles. [Pg.208]

The use of electrogenerated bases was reported for the deconjugative alkylations of a,jS-acetylenic esters by electrolysing mixtures of the esters and alkyl iodides at a Pt cathode in HMPA or DMF solutions containing tetrabutylammonium iodide Some examples... [Pg.588]

Kende AS, Toder BH (1982) Stereochemistry of Deconjugative Alkylation of Est Dienolates. Stereospecific Total Symthesis of the Litsenolides. J Org Chem 47 163... [Pg.246]

Chiral lactones (336) have been prepared in high optical yields using bromomethylacrylate as the electrophile in condensations with chiral sulphoxides similar optical yields of lactones (336) can also be obtained from condensations between aldehydes and chiral 2-(stannylmethyl)propenamides [cf. (335) Bu Sn in place of Me Si amide]. Deconjugative alkylation of... [Pg.135]

A deconjugative alkylation procedure has been used to contruct... [Pg.136]

The synthesis began with cyclopentan-l,3-dione 75. A Robinson annela-tion gave 77 via intermediate trione 76. Reduction of the more electrophilic of the two ketones gave 78, which was protected as tetrahydropyranyl ether 79. Deconjugative alkylation of 79 gave 80. Hydrolysis of the THP protecting group and reduction of the ketone (pseudo-axial delivery of hydride) provided 81/82. [Pg.454]

Alkylation of a,6-unsaturated carbonyl compounds usually occurs in the a-position, but it has been shown that deconjugative alkylation can occur in the presence of hexamethylphosphoramide (HMPA). ... [Pg.262]

Kende, A. S. and Toder, B. H., Stereochemistry of deconjugative alkylation of ester dienolates stereospecific total synthesis of the htsenoHdes, /. Org. Chem., 47,167,1982. [Pg.1447]


See other pages where Alkylation deconjugative is mentioned: [Pg.111]    [Pg.139]    [Pg.209]    [Pg.472]    [Pg.351]    [Pg.503]    [Pg.254]    [Pg.28]    [Pg.43]    [Pg.45]    [Pg.138]   
See also in sourсe #XX -- [ Pg.4 , Pg.38 ]

See also in sourсe #XX -- [ Pg.4 , Pg.38 ]




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