Method for synthesizing 2,7-dimethyl-2,4,6-octatriene-1,8-dialdehyde

A method for synthesizing 2,7-dimethyl-2,4,6-octatriene-1,8-dialdehyde, comprising the following steps:

• (1) adding acetaldehyde diethyl acetal and ethyl-(1-propenyl)-ether under effects of a catalyst at a temperature of −10° C.˜0° C. to produce 1,1,3-triethoxy-2-methyl-butane;
• wherein the catalyst is ferric chloride or aluminum chloride;
• (2) pyrolysis synthesizing 1,1,3-triethoxy-2-methyl-butane under catalytic effects of isoquinoline and p-Toluenesulfonic acid at a temperature of 180-200° C. to produce 1-ethoxy-2-methyl-1,3-butadiene;
• (3) dissolving 1-ethoxy-2-methyl-1,3-butadiene in anhydrous ethanol solvent for synthesis with a phase transfer catalyst and a chlorinating agent at a temperature of −5˜0° C. to generate 4,4-diethoxy-3-methyl-1-chloro-butene;
• wherein the phase transfer catalyst is cetyl-trimethyl ammonium bromide, the chlorinating agent is trichloroisocyanuric acid;
• (4) combining 4,4-diethoxy-3-methyl-1-chloro-butene with triphenylphosphine at a temperature of 60˜65° C. to produce a phosphonic salt;
• and
• (5) condensing the phosphonic salt under effects of hydrogen peroxide at a temperature of 0˜5° C. in conjunction with sodium carbonate solution to generate 1,1,8,8-tetraethoxy-2,7-dimethyl-2,4,6-octatriene at pH=8˜10;
• and
• then hydrolyzing under acidic conditions to synthesize 2,7-dimethyl-2,4,6-octatriene-1,8-dialdehyde.