138958-72-2

Upstream product

• 123-11-5 4-methoxy-benzaldehyde 
• 24393-56-4 ethyl (E)-3-(4-methoxyphenyl)prop-2-enoate 
• 53484-50-7 (E)-p-methoxy-cinnamyl alcohol 
• 90841-43-3 (E)-4-methoxycinnamyl bromide 
• 603-35-0 triphenylphosphine 

Downstream Products

• 171867-01-9 Methyl α-azido-2-<(2E,4E)-4-(p-methoxyphenyl)buta-1,3-dienyl>cinnamate 
• 134272-09-6 (1S,8R,9S)-9-(4-Methoxy-phenyl)-12-aza-tricyclo[6.3.2.0^2,7]trideca-2,4,6,10,12-pentaene-13-carboxylic acid methyl ester 
• 171732-80-2 2-[(1E,3E)-4-(4-Methoxy-phenyl)-buta-1,3-dienyl]-benzaldehyde 
• 74026-45-2 cis-2,3-Dihydro-3-<2-(4-methoxyphenyl)vinyl>-2-phenylfuran 
• 74026-41-8 2-<4-(4-Methoxyphenyl)-1(Z),3(E)-butadienyl>-3-phenyloxiran 
• 74026-41-8 2-<4-(4-Methoxyphenyl)-1(E),3(E)-butadienyl>-3-phenyloxiran 

Relevant academic research and scientific papers

6- and 8?-Ringschlussreaktionen von 2-Oxaheptatrienyl-Dipolen: Synthese von 3-Vinyl-2,3-dihydrofuranen und 2,3(6,7)-Dihydrooxepinen

The thermally induced ring expansion reactions of several butadienyloxiranes are described.The 3(E)-configurated epoxytrienes 11 are transformed predominantly into cis-3-vinyl-2,3-dihydrofurans 15, the trans-isomers 16 being formed as a minor component only with the derivatives a, c, and h.In contrast, thermolysis of the 3(Z)-butadienyloxiranes 12 leads always to a mixture of fivemembered ring products (15/16) and, additionally, dihyrooxepins (17 and 29, resp.).As mechanism of the ring expansion reactions a multistep sequence is proposed with 2-oxaheptatrienyl dipoles as intermediates, which undergo electrocyclisation with participation of either six or eight electrons leading to dihydrofurans and dihydrooxepins, resp.With relation to 1,7-cyclisation reactions of other extended dipole systems the importance of the stereochemistry in the starting materials is emphasised.