3917-38-2

Upstream product

• 59057-30-6 (1E)-1-(2,6,6-trimethylcyclohex-1-enyl)-3-methyl-1,4-pentadien-3-ol 
• 64-19-7 acetic acid 
• 3917-39-3 (2E,4E)-3-methyl-5-(2,6,6-trimethyl-1-cyclohexenyl)-2,4-pentadien-1-ol 
• 108-24-7 acetic anhydride 
• 59633-88-4 2-(bromomethyl)-1,3,3-trimethylcyclohex-1-ene 
• 78-70-6 3,7-dimethylocta-1,6-dien-3-ol 
• 432-25-7 2,6,6-trimethylcyclohex-1-enecarbaldehyde 
• 32659-14-6 4-bromo-3-methyl-2-buten-1-ol acetate 
• 24529-80-4 (E)-1-O-acetyl-4-chloro-3-methyl-2-buten-1-ol 

Downstream Products

• 55497-46-6 1,5,5-Trimethyl-6-[(E)-3-methyl-penta-2,4-dien-(E)-ylidene]-cyclohexene 
• 144318-19-4 β-ionylideneethanol methyl ether 
• 55732-70-2 5-(2,6,6-trimethyl-cyclohex-1-enyl)-3-methyl-1-chloro-penta-2,4-diene 
• 38987-92-7 3-methyl-5-bromo-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3-pentadiene 
• 53282-28-3 [(2E,4E)-3-methyl-5-(2,6,6-trimethylcyclohex-1-en-1-yl)penta-2,4-dienyl]triphenylphosphonium chloride 
• 62285-98-7 5-(2,6,6-trimethylcyclohexenyl)-3-methyl-2,4-pentadienyltriphenylphosphonium bromide 
• 127-47-9 Retinol acetate 
• 79-81-2 retinyl palmitate 

Relevant academic research and scientific papers

Preparation method of vitamin A acetate intermediate C15 and vitamin A acetate

The invention provides a preparation method of a vitamin A acetate intermediate C15 and vitamin A acetate. The method comprises the following steps: taking 1-halogenated-2-methyl-4-acetoxy-2-butene asa raw material, preparing a corresponding Wittig reagent through a substitution reaction with triphenylphosphine or triester phosphite, then carrying out a Wittig reaction with beta-cyclocitral, hydrolyzing an ester group under an alkaline condition, acidifying to obtain a corresponding halide, and carrying out a substitution reaction with triphenylphosphine or triester phosphite again to prepareC15. The vitamin A acetate can be prepared by carrying out a Wittig reaction on the obtained C15 and 2-methyl-4-acetoxy-2-butenal under an alkaline condition. The method has the advantages of singlereaction type, easy operation and realization of reaction conditions, safe and environment-friendly operation, simple post-treatment and low cost; and the reaction activity is strong, the reaction selectivity is high, the atom economy is high, and the target product yield and purity are high.

Preparation method of vitamin A ester intermediate C15 and vitamin A ester

The invention provides a preparation method of a vitamin A ester intermediate C15 and vitamin A ester. The method comprises the following steps: carrying out a halogenation reaction and a cyclizationreaction on 3, 7-dimethyl-3-hydroxy-1, 6-octadiene as an initial raw material, carrying out a substitution reaction on the obtained product and triphenylphosphine or triester phosphite to prepare a corresponding Wittig reagent, carrying out a Wittig reaction on the Wittig reagent and 2-methyl-4-acetoxy-2-butenal, performing acidifying, hydrolyzing and acidifying the obtained product, and carryingout a substitution reaction on the hydrolyzed and acidified product and triphenylphosphine or triester phosphite to prepare C15. The vitamin A ester can be prepared by carrying out a Wittig reaction on the obtained C15 and 2-methyl-4-R3 substituent carbonyloxy-2-butenal. The method has the advantages of single reaction type, easy operation and realization of reaction conditions, safe and environment-friendly operation, simple post-treatment and low cost; and the reaction activity is strong, the reaction selectivity is high, the atom economy is high, and the target product yield and purity arehigh.

Ionic Photodissociation of Polyenes via a Highly Polarized Singlet Excited State

Several polyene acetates and polyene methyl ether were prepared.Upon direct excitation these polyenes undergo ionic photodissociation from their singlet excited states.Triplet-sensitization experiments on these polyenes revealed that the ionic photodissociation process is restricted to singlet excited states.The rationale put forward is that the polyene chromophore undergoes charge separation/polarization in the singlet excited state, which leads to ionic photodissociation.