Tri methyl ethers

The structures of partially benzoylated derivatives of 1,6-anhydro-4, 6 -0-benzylidene-/3-maltose were established by methylation studies.51 During the course of this investigation, 2,3- and 3,3 -di- and 2,3,3 -tri-methyl ethers of l,6-anhydro-4, 6 -0-benzylidene-/3-maltose were prepared by using diazomethane-boron trifluoride etherate reagent. Methyl [methyl 2,3-di-0-methyl-4-0-(2,3,4,6-tetra-0-methyl-a -D-glucopyranosyl)-/3-D-glucopyranosid]uronate (15) has been synthe-... 

Ether cleavage (1, 30 3, 7-8). Another example when phloroacetophenone tri-methyl ether (1) is heated with aluminum chloride at 110°, it is converted into the dimethyl ether (2).12 Likewise, the 5-methoxyl group in a polymethoxyflavone under-... 

Gee and Walker reported the separation of such methylated glucose and fructose derivatives, mainly tetra- and tri-methyl ethers, as would arise from methylated sucrose derivatives. At the same time, they showed that fully methylated di- and tri-saccharides could be separated by gas chromatography. In a study on sucrose lactate, Percival and Young showed that the isomeric methyl 1,3,4-, 1,3,6-, and 1,4,6-tri-O-methyl-D-fructosides have similar retention times on 15% butanediol succinate, but are resolved on IM polyphenyl ether or 10 ethylene glycol adipate. 

Obtained by Friedel-Crafts acylation of pyrogallol tri-methyl ether with m-chlorophenylacetyl chloride in the presence of aluminium chloride in carbon disulfide for 30 min (54%) [5370]. m.p. 111-112° [5370] HNMR[5370],... 

Hydroxy-3,7,4 -trimethoxy-flavone (Kaempferol 3,7,4 -tri-methyl ether) (186) 13U 150... 

Dihydroxy-3,7,4 -trimeth-oxyflavone (Quercetin 3,7,4 -tri-methyl ether=Ayanin) (200) 122,127... 

Dihydroxy-3,7,3 -trimethoxy-flavone (Quercetin 3,7,3 -tri-methyl ether = Pachypodol) (201) 124... 

The alkynylation of estrone methyl ether with the lithium, sodium and potassium derivatives of propargyl alcohol, 3-butyn-l-ol, and propargyl aldehyde diethyl acetal in pyridine and dioxane has been studied by Miller. Every combination of alkali metal and alkyne tried, but one, gives the 17a-alkylated products (65a), (65c) and (65d). The exception is alkynylation with the potassium derivative of propargyl aldehyde diethyl acetal in pyridine at room temperature, which produces a mixture of epimeric 17-(3, 3 -diethoxy-T-propynyl) derivatives. The rate of alkynylation of estrone methyl ether depends on the structure of the alkyne and proceeds in the order propar-gylaldehyde diethyl acetal > 3-butyn-l-ol > propargyl alcohol. The reactivity of the alkali metal salts is in the order potassium > sodium > lithium. 

Treatment of commercially available and symmetrical 3,4,5-tri-methoxytoluene (37) with iodine, periodic acid, and acetic acid under the conditions of Suzuki19 results in the formation of symmetrical diiodide 38 in 93 % yield. Although only one of these newly introduced iodine atoms is present in intermediate 13, both play an important role in this synthesis. Selective monodemethylation of 38 with boron trichloride furnishes phenol 39 in 53% yield together with 13 % of a regioisomer. Evidently, one of the Lewis-basic iodine substituents coordinates with the Lewis-acidic boron trichloride and directs the cleavage of the adjacent methyl ether... 

Pentaerythritol Tetrakis[tris(difluoramino) methyl Ether] (FA-PE). C9H8F24N1204 mw... 

Methyl Acrylate CH2=CHCOOCH3 Non-inhibitors such as Biphenyl, Bibenzyl, Tri-phenyl, etc Methyl Acrylate Vap plus air > Ambient > 120 Inhibitor—H ydro quino ne or Methyl Ether of Hydro-quinone 10-20ppm. Store Store below 10° no inert atmosphere. No sparks 18.58-18.8 463 Self polymerizing above ambient press temp accelerates polymerization... 

Methyl 2,4,6-tri-0-acetyl-/3-D-glucopyranoside afforded the 2-methyl ether in 66% yield on methylation under the Purdie conditions.566 A similar 0-2 — 0-3 acyl rearrangement was observed on... 

---