O-methylation carbonate

Thus, it can be concluded that the loss of methyl groups is mainly obtained via the two mechanisms, polycondensation and crosslinking. Decomposition of the methyl carbon line in two separate signals at 20 and 24 ppm (p- and o-methyl carbons, respectively), makes possible the observation of different reactivities of o- and p-methyl groups in collidine. The p-Methyl reactions occur only when most of the o-methyl functions have disappeared 239). 

In addition to alcohols, some other nucleophiles such as amines and carbon nucleophiles can be used to trap the acylpalladium intermediates. The o-viny-lidene-/j-lactam 30 is prepared by the carbonylation of the 4-benzylamino-2-alkynyl methyl carbonate derivative 29[16]. The reaction proceeds using TMPP, a cyclic phosphite, as a ligand. When the amino group is protected as the p-toluenesulfonamide, the reaction proceeds in the presence of potassium carbonate, and the f>-alkynyl-/J-lactam 31 is obtained by the isomerization of the allenyl (vinylidene) group to the less strained alkyne. 

Magnesium methyl carbonate [Magnesium, methoxyOnethyl cjibonato-O-], 121 Maleic acid, methyl ester [2 Butenedioic acid, (Z)-, dimethyl ester], 63 Maganese, tricarbonyl [ (1,2,3,4,5-rj)-l -... 

The carbon atoms of the parent chain are numbered according to 2-Carb-2.2.1. If a unique numbering is required for the branch(es) (e.g. for X-ray orNMR work), the carbon atoms may be given the locant of the appropriate branch point, with the internal branch locant as superscript, e.g. 42 for position 2 of the branch at position 4 of the main chain. This style of branch numbering is not to be used for naming purposes e.g. the side-chain-methylated derivative of compound 5 is named 4,6-dideoxy-3-C-[(I )-1 -methoxyethyl]-D-n7w-hexose, and not as a s -O-methyl derivative. 

In the spectrum of fully reductively [ C] methylated glycophorin A, the resonance at 42.8 p.p.m. must correspond to the N, N -di[ C]methylated, N-terminal amino acid residue. The ratio of the integrated intensities of the N, N -di[ C]methylLeu resonance to the N, N -di[ C]methyllysine resonances is 5 1, as expected. The integration values determined were valid, because the recycle times of spectra in Figs. 3B, 3C, and 3D were twice the spin-lattice relaxation-times (Tj values) of those of the di[ C]methyl carbon atoms, and also because the n.O.e. values of the N, N -di[ C]methyl and N, N -di[ C]methyl carbon atoms were equivalent. ... 

Directed lithiation of aromatic compounds is a reaction of broad scope and considerable synthetic utility. The metalation of arenesulfonyl systems was first observed by Gilman and Webb and by Truce and Amos who reported that diphenyl sulfone is easily metalated at an orf/io-position by butyllithium. Subsequently, in 1958, Truce and coworkers discovered that metalation of mesityl phenyl sulfone (110) occurred entirely at an orf/io-methyl group and not at a ring carbon, as expected. Furthermore, refluxing an ether solution of the lithiated species resulted in a novel and unusual variation of the Smiles rearrangement and formation of 2-benzyl-4,6-dimethyl-benzenesulfinic acid (111) in almost quatitative yield (equation 78). Several other o-methyl diaryl sulfones have also been shown to rearrange to o-benzylbenzenesulfinic acids when heated in ether solution with... 

Figure 7.7 Separation of ethynyl estrogens on silica gel 60 HPTLC plates using two 15-min developments in the solvent system hexane-chloroform-carbon tetrachloride-ethanol (7 18 22 1 v/v). Identification O methyl green (lane marker) 1 17a-ethynylestradiol ...

Calcium carbide, 32, 70 Calcium carbonate, 32, 81 Calcium formate, 31,102 CAPROIC ACID, e-AMINO, 32, 13 e-Caprolactam, 31, 72 32, 15 e-CAPROLACTIM, O-METHYL-, 31, 72 CAPRONITRILE, a-ETHYL, 32, 6S Caproyl chloride, 31, 71 CARBANILINONITRILE, O-CHLORO, 31, 19... 

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