## Abstract The identity and structures of warifteine and methylwarifteine, two tertiary bisbenzylisoquinoline alkaloids of an unusual type, were elucidated and verified by 2D NMR spectroscopy. Complete ^1^H and ^13^C NMR spectral assignments were obtained. Copyright Β© 2003 John Wiley & Sons, Ltd.
Solasodine and diosgenin: 1H and 13C assignments by two-dimensional NMR spectroscopy
β Scribed by Raman Puri; Tuck C. Wong; Ravi K. Puri
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 393 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0749-1581
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β¦ Synopsis
Abstract
Solasodine and diosgenin have been widely used as starting materials for the partial synthesis of cortisone, progresterone and C21 steroidal derivatives (oral contraceptives). This study involved the total ^1^H and ^13^C spectral assignments of these two important compounds by using twoβdimensional NMR techniques (COSY, CSCM and HMBC), and resulted in unambiguous spectral assignments, especially in the convoluted regions of the spectra (^1^H, 0.7β2.0 ppm; ^13^C, 28β35 ppm).
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The total assignment of the 13C and the ' H NMR spectra of four derivatives of 1,3diaza-2,4-diboranaphthalene has been performed. The interpretation of the spectra was achieved from the concerted application of direct and long-range heteronuclear chemical shift correlation and homonuclear COSY two-d
## Abstract ^1^H NMR spectra of eight naturally occurring brassinosteroids, plant hormones with a steroid skeleton, and five synthetic analogues were analysed by COSY and longβrange COSY measurements. Based on the ^1^H resonances, the ^13^C signals were assigned by a combination of Cο£ΏH COSY and lon