Meta-hydroxymethylation

Formaldehyde reacts with lignin at the 2- and 6-positions of the phenyl-propane medium in 10 to 20% aqueous dioxane containing 0.4 to IN hydrochloric acid, to afford meta hydroxymethylated intermediates. This results in a reactive mefa-hydroxymethylated lignin intermediate capable of being modified with various reagents or by reacting with itself. 

In the above paragraph it was shown that the lignin Cg units can be polymerized at the 2- and 6-positions with formaldehyde in acidic aqueous dioxane. The polymerization reaction proceeds presumably via a hydrox-ymethylated intermediate which was isolated in low yields only when large excesses of formaldehyde were employed. If the hydroxymethylation of the meta position can be achieved in high yield it would clearly afford a very... 

The reactivity of the hydrocarbons increases in the order ortho < meta < para in the liquid-phase catalytic oxidation of methyl derivatives of biphenyl into acids by air. The mechanism of the oxidation of hydroxymethylbiphenyls and hydroxymethyl-benzenes involves the formation of an unstable cation radical, which is then stabilized by emitting a proton, giving hydroxybenzyl radical.243... 

Recently 7,8-dimethoxy isochroman-3-one 48 has been synthesised by an interesting route which involves hydroxymethylation of meta-hydroxy phenyl acetic acid in presence of phenylboronic acid. The presence of the latter in the reaction medium specifically brings about hydroxymethylation ortho to the phenolic group... 

In the search for agents to increase bone formation through bone morphogenetic proteins, 3-hydroxymethyl-4-glutaryl CoA reductase inhibitors (statins) were discovered to increase bone density in animal models. Interest in the potential skeletal benefits of statins was heightened by the discovery that bisphosphonates may also affect cholesterol biosynthesis, but at a different step than statins. Although observational studies have linked statin use with decreased fracture risk, a large case-control study did not demonstrate reduction in fracture risk for statin-treated patients. A meta-analysis casts doubt on a protective effect of statins (odds ratio for hip fracture, 0.87 95% Cl 0.48 to 1.58). 02... 

TMEDA. See 1,3-Diaminopropane N,N,N, N -Tetramethylethylenediamine TMG. See Tetramethyl guanidine TMG acid. See 3,3-Tetramethylene glutaric acid TMI. See p-Tolyl isocyanate m-TMI. Seem-Tolyl isocyanate 3-[(Prop-1-en-2-yl) phenyl] prop-2-yl isocyanate o-TMI. See o-Tolyl isocyanate p-TMI. See p-Tolyl isocyanate TMi (Meta). See 3-[(Prop-1-en-2-yl) phenyl] prop-2-yl isocyanate TML. See Tetramethyl lead TMOS. See Tetramethoxysilane TMP. See Trimethylolpropane 2,3,6-TMP. See 2,3,6-Trimethylphenol 2,4,-TMP. See Isooctane TMPC. See Tetrakis (hydroxymethyl) phosphonium chloride... 

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