Optically active amines. XX. Application of the salicylidenimino chirality rule to cyclic terpene amines

The salicylidenamino chirality rule: a method for the establishment of the absolute configurations of chiral primary amines by circular dichroism

“…)-61a showing a bisignate CD curve (Figure 9), interpreted in terms of vibronic coupling (section IVA). 33 For the thujylamines (63) and the isothujylamines (64), the interpretation of the CD spectra of their N- e May be due to the n -+ ir* transition of the azomethine group, t Ellipticity measurements not of quantitative significance.…”

Optically active amines. 26. Spectral observations on chiral Schiff bases

“…The same oxadiazolylpyridine 3 (R = Me; Ri = H) could be prepared also by hydrolysis of the formyl drivative 3 (R = Me; Ri = CHO), obtained by treatment of 4-aminopyrido[2,3d]pyrimidine 3-oxide (4, R = H) with acetic anhydride. This transformation parallels the ring opening of adenine 1-oxide which proceeds through the O-acetyl derivative which subsequently undergoes ring opening and recyclization into a oxadiazole derivative.7 Finally, if the amidoxime 2 (R = H) was heated with triethyl orthoformate, compound 3 (R = Ri = H) was obtained as byproduct (1%) together with 4 (R = H) as the main product (89%). Since one may postulate that the jV-oxide (4, R = H) in this reaction may be formed from 3 (R = Ri = H) in a thermal reaction, we have performed a separate experiment and established that this conversion does not occur under the conditions of the above reaction.…”