Structure and atropisomerisation of new diastereomeric gossypol Schiff bases with (R)-(+)-2-amino-3-benzyloxy-1-propanol studied by NMR, ECD and DFT methods

摘要: Abstract Gossypol Schiff base with (R)-(+)-2-amino-3-benzyloxy-1-propanol 1 was synthesised and resolved by HPLC method into diastereomers to study their atropisomerisation process. The spectroscopic analysis performed one- two-dimensional NMR, UV–vis FT-IR methods indicated that the compound exists in solution as an enamine-oxo tautomer. ECD measurements TD-DFT calculations allowed us unambiguously determine configuration about axially chiral biaryl moiety of 1. conditions processes diastereopure gossypol bases (SAX,R)-1 (RAX,R)-1 were determined on basis NMR measurements. Exposure sunlight light at λ = 254 nm significantly accelerated when compared its rate dark.