51544-65-1

Upstream product

• 123-73-9 trans-Crotonaldehyde 
• 2181-98-8 <3-carbomethoxy-propen-(2)-yl-(1)>-triphenylphosphoniumbromide 
• 72967-11-4 (3-methoxycarbonyl-2-propenyl)triphenylphosphonium bromide 
• 189943-34-8 (E)-4-(Triphenyl-λ⁵-arsanylidene)-but-2-enoic acid methyl ester 
• 80400-46-0 (E,E)-trimethyl(1,3-pentadien-1-yl)silane 
• 922-67-8 propynoic acid methyl ester 

Relevant academic research and scientific papers

Tandem Michael addition/ylide olefination reaction for the synthesis of highly functionalized cyclohexadiene derivatives

A tandem Michael addition/ylide olefination for the rapid creation of highly functionalized cyclohexadiene is developed. The tandem annulation reactions afford versatile cyclohexadienes in good to excellent isolated yields. This method has been successfully applied to the synthesis of three biologically active molecules.

Condensations of Crotonate Arsonium Ylide with Conjugated Carbonyl Compounds

Condensations of methyl 4-(triphenylarsoranylidene)-2-butenoate 1a and conjugated carbonyl compounds give 1,3-cyclohexadiene-1-carboxylates and/or acyclic trienes in superior yields compared to the condensations with the phosphonium analogue 1b. However, the reaction of 1a and ethyl 2-cyano-5-methyl-2,4-hexadienoate 7 gave a mixture of two diastereomeric trans-bisvinylcyclopropanecarboxylates 9.

The Diels-Alder Route to Allylsilanes from 1-Trimethylsilylbutadienes

The synthesis and Diels-Alder reactions of 1-trimethylsilylbutadiene (3) and its 3-methyl (17), 3-trimethylsilyloxy (20), 4-methyl (4), and 4-trimethylsilyl (6) derivatives are reported.The silyl group reduces somewhat the rate of the Diels-Alder reactions, and has, if anything, a small 'ortho'-directing effect on the regioselectivity in the reactions of (3) with methyl acylate, methyl propiolate, citraconic anhydride, and 2,6-dimethylbenzoquinone.The other substituent in the dienes (17), (20), and (4) is therefore the major influence on the regioselectivity in the reactions of these dienes with methyl acrylate and methyl propiolate.The products of the Diels-Alder reactions of (3), (17), and (4) are allylsilanes, which undergo clean protodesilylation with acid, and, with the acid and ester derived from the maleic anhydride adduct of (3), undergo epoxidation and sulphenylation reactions giving an allyl alcohol (33) and an allyl sulphide (37), respectively.The adducts from (20) can be hydrolysed to β-silylketones, which can be converted into enones by bromination. 1-Pentamethyldisilylbutadiene (15) is no more reactive and no more regioselective than (3).The 'ortho'-adduct (42) from the reaction of (3) and methyl propiolate aromatises with DDQ to give methyl m-trimethylsilylbenzoate (53) in high yield, in a reaction involving rearrangement of the silyl group, even though a direct dehydrogenation is an available pathway.