Abstract
Byakangelicol (I) was treated with dimethylamine or piperidine in benzene below 60°(condition A), in methanol near room temperature (condition B), and in benzene in a sealed tube at 125°(condition C). Amine amides (VIII and IX), neutral amides (X and XII), and neutral amides (XI and XIII) were obtained under conditions A, B, and C, respectively. Results of ultraviolet and nuclear magnetic resonance measurements and chemical treatment showed that X-XI and XII-XIII were in geometrical relationship, X and XII being cis isomers and XI and XIII trans isomers. An equilibrium between XII and XIII in a 87 : 13 ratio was established within 25 hr when either XII or XIII in 0.1N NaOH-EtOH was exposed to diffused light.
