88018-07-9

Upstream product

• 77733-81-4 (2E)-4-<2-(3-Cyan-trans-3-phenyl-2-oxiranyl)phenoxy>-2-butensaeure-methylester 
• 3052-50-4 monomethyl maleate 
• 925230-65-5 methyl (Z)-4-hydroxy-but-2-enoate 
• 89-95-2 2-methyl-benzyl alcohol 
• 56699-18-4 cis-4-bromo-2-butenoic acid methyl ester 
• 1117-71-1 methyl 4-bromocrotonate 
• 90-02-8 salicylaldehyde 

Downstream Products

• 1181664-48-1 C₁₆H₁₈O₆ 
• 28809-07-6 methyl (E)-4-(2-formylphenoxy)but-2-enoate 

Relevant academic research and scientific papers

SUBSTITUTED CHROMANES, ANALOGS THEREOF, AND METHODS OF USE AND SYNTHESIS

Disclosed are chromane compounds, analogs thereof, and methods of their synthesis and use. The compounds may be synthesized by methods involving reductive annulations of arylidene malonates with unsaturated electrophiles using photoredox/Lewis acid cooperative catalysis. The compounds may be formulated in a pharmaceutical composition for treating one of the aforementioned diseases or disorders.

Synthesis of Chromen[4,3-b]pyrrolidines by Intramolecular 1,3-Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

Azomethine ylides, generated from imine-derived O-cinnamyl or O-crotonyl salicylaldeyde and α-amino acids, undergo intramolecular 1,3-dipolar cycloaddition, leading to chromene[4,3-b]pyrrolidines. Two reaction conditions are used: (a) microwave-assisted heating (200 W, 185 °C) of a neat mixture of reagents, and (b) conventional heating (170 °C) in PEG-400 as solvent. In both cases, a mixture of two epimers at the α-position of the nitrogen atom in the pyrrolidine nucleus was formed through the less energetic endo-approach (B/C ring fusion). In many cases, the formation of the stereoisomer bearing a trans-arrangement into the B/C ring fusion was observed in high proportions. Comprehensive computational and kinetic simulation studies are detailed. An analysis of the stability of transient 1,3-dipoles, followed by an assessment of the intramolecular pathways and kinetics are also reported. The two-component synthesis of chromene[4,3-b]pyrrolidines has been achieved under two different conditions. The strategy was used to obtain N-sulfonylated adducts with interesting biological activity. Calculations show that formation of W and S′ 1,3-dipoles determines the stereochemical outcome of the reaction, which involves asynchronous transition structures.

PPh3-mediated intramolecular conjugation of alkyl halides with electron-deficient olefins: Facile synthesis of chromans and relevant analogues

With the mediation of phosphine, the direct intramolecular coupling of two electrophiles-alkyl halides with electron-deficient olefins-has been successfully realized in an intramolecular conjugate addition manner. The reaction provides a new approach for

Catalytic intramolecular formal [3 + 2] cycloaddition for the synthesis of benzobicyclo[4.3.0] compounds

In the presence of 20 mol % of tributylphosphine, tert-butyl carbonate substrate 3a undergoes smoothly an intramolecular formal [3 + 2] cycloaddition reaction at room temperature to give benzobicyclo[4.3.0] compounds in 99% yield with a 19/81 ratio of 2a

Microwave-assisted solvent-free intramolecular 1,3-dipolar cycloaddition reactions leading to hexahydrochromeno[4,3-b]pyrroles: scope and limitations

We report the microwave-assisted solvent-free synthesis of hexahydrochromeno[4,3-b]pyrroles. Intramolecular 1,3-dipolar cycloadditions proceed under these conditions within 15-40 min in 16-84% yields. An influence of the microwave irradiation upon various [3+2] cycloaddition reaction intermediates was studied. Additionally, a scope and limitations of these reactions including an influence of the dipolarophile geometry upon the cycloaddition selectivity and steric demands of the dipole upon its reactivity were also disclosed. These observations led us to postulate a preferable transition state of the reaction. Finally, an influence of the microwave irradiation to the isomerization of activated olefins was also described.

INVESTIGATIONS ON INTRAMOLECULAR CYCLOADDITION REACTIONS OF PHOTOCHEMICALLY GENERATED CARBONYL YLIDES

Upon photoexcitation of appropriately substituted oxiranes ring opening leads to carbonyl ylides which undergo intramolecular cycloaddition reactions affording annelated and/or bridged tetrhydrofurans.