| 中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
|---|---|---|---|---|
| —— | 2-allyloxy-2-methoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline | 857270-88-3 | C8H14N2O3 | 186.211 |
| —— | 2-(3-butyn-1-oxy)-2-methoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline | 143843-62-3 | C9H14N2O3 | 198.222 |
| —— | 2,5-dihydro-2,2-dimethoxy-5,5-dimethyl-1,3,4-oxadiazole | 138723-90-7 | C6H12N2O3 | 160.173 |
| —— | 2-Methoxy-5,5-dimethyl-2-pent-3-ynoxy-1,3,4-oxadiazole | 189142-15-2 | C10H16N2O3 | 212.249 |
| —— | 2-methoxy-5,5-dimethyl-2-(4-pentyn-1-oxy)-Δ3-1,3,4-oxadiazoline | 154027-20-0 | C10H16N2O3 | 212.249 |
| —— | Methyl 5-[(2-methoxy-5,5-dimethyl-1,3,4-oxadiazol-2-yl)oxy]pent-2-ynoate | 189142-23-2 | C11H16N2O5 | 256.258 |
| —— | 2-Methoxy-5,5-dimethyl-2-<2-(trimethylsilyl)ethoxy>-Δ3-1,3,4-oxadiazoline | 177719-17-4 | C10H22N2O3Si | 246.382 |
| —— | 7-(2-methoxy-5,5-dimethyl-2,5-dihydro[1,3,4]oxadiazol-2-yloxy)-hept-3-en-2-one | 757231-84-8 | C12H20N2O4 | 256.302 |
| —— | 6-(2-Methoxy-5,5-dimethyl-2,5-dihydro-[1,3,4]oxadiazol-2-yloxy)-hex-2-ynoic acid methyl ester | 189142-33-4 | C12H18N2O5 | 270.285 |
| —— | methyl (2E,4E)-7-[(2-methoxy-5,5-dimethyl-1,3,4-oxadiazol-2-yl)oxy]hepta-2,4-dienoate | 757231-66-6 | C13H20N2O5 | 284.312 |
| —— | (2E,4E)-8-(2-Methoxy-5,5-dimethyl-2,5-dihydro-[1,3,4]oxadiazol-2-yloxy)-octa-2,4-dienoic acid methyl ester | 757231-73-5 | C14H22N2O5 | 298.339 |
| —— | (2E,4E)-9-(2-Methoxy-5,5-dimethyl-2,5-dihydro-[1,3,4]oxadiazol-2-yloxy)-nona-2,4-dienoic acid methyl ester | 757231-75-7 | C15H24N2O5 | 312.366 |
| —— | 2-(2-cyclobutanonemethoxy)-2-methoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline | 312909-11-8 | C10H16N2O4 | 228.248 |
| —— | 2-[(2-Methoxy-5,5-dimethyl-1,3,4-oxadiazol-2-yl)oxymethyl]cyclohexan-1-one | 609811-61-2 | C12H20N2O4 | 256.302 |
| —— | 2-(1,1-Dideuterioprop-2-enoxy)-2-methoxy-5,5-dimethyl-1,3,4-oxadiazole | 857270-90-7 | C8H14N2O3 | 188.195 |
| —— | [2,2-Dideuterio-2-[(2-methoxy-5,5-dimethyl-1,3,4-oxadiazol-2-yl)oxy]ethyl]-trimethylsilane | 381228-40-6 | C10H22N2O3Si | 248.366 |
Dimethoxycarbene, generated at 110 °C by thermolysis of 2,2-dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline, displaces fluoride from aromatic rings that are activated with electron-withdrawing groups. Intermolecular substitution on Sanger's reagent and on hexafluorobenzene are reported, together with intramolecular substitution by a dioxycarbene with a tethered aryl group. Keywords: aromatic substitution, aryl(dimethoxy)fluoromethanes, aryl fluoride, dialkoxycarbene, nucleophilic substitution.
A cyclopropanone, a cyclopropenone, cyclobutanones, a cyclobutane-1,3-dione, and a cyclobutene-1,2-dione reacted with dimethoxycarbene to afford acetals of the next larger ring by formal insertion of the carbene into a CC bond α to the carbonyl group. When either of two saturated α-ring carbons could be involved in the process, the ring expansion was selective, affording primarily the product of apparent insertion into the more substituted ring bond. With 2,3-dimethoxycyclobutene-1,2-dione, insertion occurred between the carbonyl groups and with β-propiolactone it occurred at the lactone bond. β-Propiolactam, however, reacted by insertion of the carbene into the NH bond.Key words: β-propiolactone, cyclobutanone, cyclobutananedione, cyclopropanone, dialkoxycarbene.
2-Acetoxy-2-methoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline undergoes two competitive 1,3-dipolar cycloreversions at 110 °C. It loses N2, presumably to afford a short-lived carbonyl ylide that fragments to acetone and acetoxy(methoxy)carbene. It also forms 2-diazopropane and the appropriate mixed anhydride. It is the only currently known source of acetoxy(methoxy)carbene. Key words: acetoxy(methoxy)carbene, 2-diazopropane, 1,3-dipolar cycloreversion.