The present paper covers a new process for the synthesis of 1-（2,6,6-trimethyl-1-cyclohexenyl）-3-methyl-2-buten-4-al with dimethyl sulfide, bromomethane and β-ionone as primary materials in four steps, via the carb...The present paper covers a new process for the synthesis of 1-（2,6,6-trimethyl-1-cyclohexenyl）-3-methyl-2-buten-4-al with dimethyl sulfide, bromomethane and β-ionone as primary materials in four steps, via the carbine reaction of dimethyl sulfide and bromomethane, the cyclization of trimethylsulfonium bromide and β-ionone, the opening of epoxy compound and isomerization of C14-aldehyde. The overall yield is 77%. The structure of the titled product was characterized by GC/MS, IR and 1H NMR. The process has many advantages such as facile low-cost materials, high conversion, short reaction time, mild reaction ondition, and less by-products. Furthermore, the part materials can be recycled, the cost and pollution are reduced, so it is feasible for industry production.展开更多
A convenient and large-scale preparation of retinoic acid 1 from β-ionone in five steps with 38% overall yield is described. The key steps are the epoxidization of 2 with a new methylated agent and the condensation ...A convenient and large-scale preparation of retinoic acid 1 from β-ionone in five steps with 38% overall yield is described. The key steps are the epoxidization of 2 with a new methylated agent and the condensation 4 with tetraethyl methylenediphophonate in one-pot procedure to prepare 6.展开更多
文摘The present paper covers a new process for the synthesis of 1-（2,6,6-trimethyl-1-cyclohexenyl）-3-methyl-2-buten-4-al with dimethyl sulfide, bromomethane and β-ionone as primary materials in four steps, via the carbine reaction of dimethyl sulfide and bromomethane, the cyclization of trimethylsulfonium bromide and β-ionone, the opening of epoxy compound and isomerization of C14-aldehyde. The overall yield is 77%. The structure of the titled product was characterized by GC/MS, IR and 1H NMR. The process has many advantages such as facile low-cost materials, high conversion, short reaction time, mild reaction ondition, and less by-products. Furthermore, the part materials can be recycled, the cost and pollution are reduced, so it is feasible for industry production.
文摘A convenient and large-scale preparation of retinoic acid 1 from β-ionone in five steps with 38% overall yield is described. The key steps are the epoxidization of 2 with a new methylated agent and the condensation 4 with tetraethyl methylenediphophonate in one-pot procedure to prepare 6.
