Methyl group inside

This has been identified as the endo isomer, i.e. the one in which the Ce methyl group is inside (Koptyug et al., 1969). As in the case of 19, when 22 is warmed to — 34°, a clean first-order reversion to the hexa-... 

Recently, Stair and coworkers [10, 11] developed a method to produce gas-phase methyl radicals, and used this to study reactions of methyl groups on Pt surfaces [12] and on molybdenum oxide thin films [13]. In this approach, methyl radicals are produced by pyrolysis of azomethane in a tubular reactor locat inside an ulttahigh vacuum chamber. This method avoids the complications of co-adsorbcd halide atoms, it allows higher covraages to be reached, and it allows tiie study of reactions on oxide and other surfaces that do not dissociate methyl halides effectively. 

On the basis of the h and C NMR, we have pictured the delivery site of BPA as illustrated in Fig. 15. There is trapped BPA between the lipid headgroup and hydrocarbon chain region most adjacent to the interface, with two methyl groups oriented toward inside... 

In allylic alcohols with A1,3 strain, the main product is syn. A methyl substituent at R4 leads to the methyl group being positioned anti to the complexed oxidant. If R4 is hydrogen, a TS with the methyl group in an inside position is favored, as shown in Figure 12.6. 

Initially, the four acetate residues (Ri) are decarboxylated into methyl groups. The resulting coproporphyrInogen III returns to the mitochondria again. The subsequent steps are catalyzed by enzymes located either on or inside the inner mitochondrial membrane. 

The pores of HZSM-5 do not have enough space to accommodate 1-MN and DMN isomers with a-methyl groups. The methylation of 2-MN over HZSM-5 yields predominantly 3, 3-DMN isomers, 2,6-, 2,7- and 2,3-DMN, with the formation of bulky a,P-DMN, 1,2-, 1,3-, and 1,6-, and 1,7-DMN. The selective formation of 2,6- and 2,7-DMN occurs inside pores, because the deactivation of external acid sites of MFI-metallosilicates by 2,4-DMQ reduces the isomerization of 2,6- and 2,7-DMN to a,(3-DMN. However, the pores of HM and HY do not contribute to the shape-selective methylation and related reactions of naphthalene and 2-MN. 

The biocidal activity of the thiadiazine (12) is probably related to the production of methyl isocyanate inside the cell by hydrolysis (equation 7). Isocyanates are known to have fungicidal properties (B-69MH1502), thought to be due to their reaction with sulfhydryl groups to form dithiocarbamates. The formation of these last mentioned compounds, by ring cleavage, might also explain the activity of 2-mercaptobenzothiazole (16). 

Methyl group proton chemical shifts in structurally related inside yohimbanes are shown in [503] and [504]. (306)... 

Ikegami s synthesis has two steps of particular interest. Allylation of the enolate of 27 puts the new allyl group on the outside and forces the old methyl group onto the inside 28. The planar enolate is an intermediate. The final step puts in both epoxides on the outside of the molecule from the dienone 29 mainly through complexation of VO+ with one of the free OH groups.9 This also makes both the right-hand 5/5 and the 5/3 cis fused.10... 

Alcohol spectra were obtained in chloroform-d and are referenced to internal tetramethylsilane. Cation spectra are referenced to tetramethylsilane contained in a capillary inside the NMR tube. The methyl group signal for the methyl-substituted carbonium ions (in nitromethane, sulfuric acid, and trifluoroacetic acid) was a doublet (J = 7 Hz). The methyne proton for these same carbonium ions appears as a quartet (J = 7 Hz). For the phenyl-substituted and unsubstituted carbonium ions, the methyne proton and methylene proton signals (respectively) were singlets. 

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