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Pelter oxidation

Many natural products display structural motifs biosynthetically derived from ortho-quinol precursors, and some even feature ortho-quinol moieties in their final structural arrangement [1, 6]. Asatone (7) and related neolignans can be put forward as classic examples of complex natural products derived from cyclodimerization of oxidatively activated simple phenol precursors (Figure 5) biomimetic syntheses of 7 have accordingly been accomplished by anodic oxidation (Section 15.2.1) and by Pelter oxidation (Section 15.2.2) of the naturally occurring phenol 9 [34, 36]. [Pg.543]

The two halogen-based methods that continue to attract organic chemists the most for the oxidative activation of arenois are the Adler oxidation and the Pelter oxidation (vide infra) ... [Pg.550]

Mild and high yielding oxidation reactions of phenol derivatives to the corresponding quinone monoacetals, quinols, and quinones using PIDA or PIFA [Eqs. (1) - (3)] have been developed independently by Kita et al. [27], Lewis et al. [28], and Pelter et al. [29], and have been utilized extensively for the syntheses of... [Pg.223]

Komblum et al. had asserted that it was necessary to convert primary iodides to tosylates for the oxidation to proceed. However, Johnson and Pelter have claimed that primary iodides can be oxidized directly. They observed that ketonic substrates failed, undergoing aldol condensation under the reaction conditions, but that hydroxy-containing halides reacted normally. For substrates insoluble in DMSO such as 1-bromododecane, they found that DME worked well as a cosolvent. The most interesting example... [Pg.654]

Pelter and Wilson have described the deprotonation of the air stable dimesitylboranes. The use of two mesityl groups represents a compromise between steric shielding of the boron against the possible complex formation with the base, and easy oxidation of the product. Alkylation of the anion generated... [Pg.199]

Although Kornblum stated that ordinary halides are not oxidized by his method but must first be converted into the tosylates, Johnson and Pelter found that DMSO... [Pg.885]

Oxidation of Carbon-Boron Bonds A. PELTER K. SMITH, University College Swansea, UK 593... [Pg.1031]

Phenylalanine and p-coumaric acid, but not 3,4-dihydrox-ycinnamic (caffeic) acid or acetate, were incorporated into podophyllotoxin (51). In Podophyllum hexandrwn (Berberi-daceae), both cinnamic and ferulic acids are incorporated into both halves of the molecule. The carbon of the 0-methyl group of ferulic acid is distributed into both rings A and C. Sinapic and 3,4,5-trimethoxycinnamic acids are not incorporated. This suggests that other oxidation and methylation occurs after the initial dimerization reaction (Jackson and Dewick, 1984 Pelter, 1986 Poulton, 1981). [Pg.118]

Experiment 66 is adapted from M. W. Pelter, R. M. Macudzinski, and M. E. Passarelli, A Microscale Oxidation Puzzle, Journal of Chemical Education, 77 (November 2000) 1481. [Pg.571]

Tri(cyclopentyl)borane in diglyme added at 0° to Li-n-hexylacetylide under hexane, the volatile solvent removed, methyl tosylate added at -78°, the cooling bath removed, warmed 2 hrs. at 40°, then oxidized with alkaline H2O2 -> product. Y 88%. F. e., also with other alkylating agents such as bromides, sulfates, or oxonium salts, protonation with methanesulfonic acid, and synthesis of mixtures of cis- and trans-ethylene derivs., s. A. Pelter, C. R. Harrison, and D. Kirkpatrick, Chem. Commun. 1973, 544. [Pg.218]


See other pages where Pelter oxidation is mentioned: [Pg.551]    [Pg.552]    [Pg.564]    [Pg.566]    [Pg.551]    [Pg.552]    [Pg.564]    [Pg.566]    [Pg.256]    [Pg.35]    [Pg.600]    [Pg.336]    [Pg.12]    [Pg.260]    [Pg.365]   
See also in sourсe #XX -- [ Pg.543 , Pg.550 , Pg.564 , Pg.566 ]




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