34036-55-0

Upstream product

• 1657-55-2 1,2-bis(4-methoxyphenyl)ethane 
• 75-36-5 acetyl chloride 
• 108-24-7 acetic anhydride 

Downstream Products

• 136559-22-3 1,2-bis<3-(1-hydroxyethyl)-4-methoxyphenyl>ethane 
• 136559-23-4 1,2-bis(3-vinyl-4-methoxyphenyl)ethane 

Relevant academic research and scientific papers

Medium-sized cyclophanes. Part 53. Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

A series of [n.2]metacyclophanenes (3) and (6) were prepared in good yields by a McMurry cyclization of 1,n-bis(3-acetyl-4-methoxyphenyl)alkanes (2) and 1,3-bis(3-formyl-4-methoxyphenyl)propane (5), respectively. Compounds 3b, 3c exist in the syn-conformation due to the steric repulsion between the methyl groups at the ethano bridge and the methoxy groups at the aromatic rings while compound 6 prefers the anti-conformation typical of [3.2]metacyclophanes. The assignment of syn-conformations has been confirmed by 1H NMR analyses and X-ray diffraction studies. Photoinduced transannular cyclization of [n.2]metacyclophanenes (3) and (6) in the presence of iodine as an oxidant afforded phenanthrene-anellated polycyclic aromatic hydrocarbons. Apparently, the rate of the photocyclization of anti-6 was found to be much faster than that of syn-3b and almost completed within 1 h. Thus, the different reactivities for the irradiation of syn- and anti-conformer were observed. The reason for the present preference for the formation of trans-dihydrophenanthrene rather than cis-dihydrophenanthrene as the intermediate might be attributable to the more stable chair form transition state than boat one and the conformational fixation to the chair form in the ground and transition state is possible in the anti-conformer.

Stereoselective Synthesis of Meta- and Three-bridged Cyclophanes with Intramolecular Photocycloaddition by Using the Steric Effect of Methoxyl Group

Key Words: Cyclophane; stereoselectivity; conformation; regioisomer; photocycloaddition; torsional angle.Dimethoxymetacyclophanes 9 (n=2,3,4,5, and 6) and 10 were stereoselectively obtained in 61-87percent yields by means of photocycloaddition.

Synthesis and Structural Analysis of Dimethoxymetacyclophanes

Dimethoxymetacyclophanes were obtained in 46-68percent yields through photocycloaddition of corresponding styrene derivatives.These metacyclophanes were assigned to be of syn-conformation (n=3,4,5, and 6) or the mixture of syn- and anti-conform