114728-58-4Relevant articles and documents
THERMAL ELECTROCYCLIC RING-OPENING OF CYCLOBUTENES: STEREOSELECTIVE ROUTES TO FUNCTIONALISED CONJUGATED (Z,E)- AND (E,E)-2,4-DIENALS
Binns, Falmai,Hayes, Roy,Ingham, Stephen,Saengchantara, Suthiweth T.,Turner, Ralph W.,et al
, p. 515 - 530 (2007/10/02)
The cyclobutenecarbaldehyde 12 undergoes thermal electrocyclic ring-opening at low temperature, producing the (2Z,4E)-hexadienal 13 exclusively.By contrast, unsymmetrical derivatives of cis-3-cyclobutene-1,2-dicarboxylic acid undergo ring-opening at 80-110 deg C with low levels of stereoselectivity, which vary according to the balance of the electronic and, to a lesser extent, the steric nature of the substituents located on the rehybridising carbon atoms.
