Preparation of two novel spermine alkaloids by E/Z isomerisation of the cinnamoyl chromophore
✍ Scribed by Bassem F. Tawil; Armin Guggisberg; Manfred Hesse
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 527 KB
- Volume
- 54
- Category
- Article
- ISSN
- 1010-6030
No coin nor oath required. For personal study only.
✦ Synopsis
The E/Z photo-isomerisation behaviour of the cinnamoyl chromophore in some cyclic polyamine alkaloids was investigated. Under daylight laboratory conditions, the alkaloid iso-18-O-methylchaenorpine (3) with an E-double bond isomerises gradually to the Z-form 18-0-methylchaenorpie (1). This can be enhanced by irradiation with visible light. On the other hand, the isomer 18-O-methylchaenorpine with a Z-double bond, photoisomerises to the E-form in 70% yield when irradiated with a low pressure mercury lamp at 253.7 run. This behaviour is also observed in the soIid phase. Thus two new alkaloids, isochaenorpine (4) and isochaenorhine (6), were produced by the photo conversion of their Z-forms.