Structures of 9-O-Demethylhomolycorine and 5α-Hydroxyhomolycorine. Alkaloids of Crinum defixum, C. scabrum, and C. latifolium. Assignment of Aromatic Substitution Patterns from 1H-Coupled 13C Spectra

Article abstract of DOI:10.1021/jo00210a031

The isolation and characterization of the major crystalline alkaloids of three Crinum species, C. defixum, C. scabrum, and C. latifolium, are reported.A new alkaloid, 5α-hydroxyhomolycorine (1) has been isolated from C. defixum.The latter plant also contains an alkaloid identified as 9-O-demethylhomolycorine which differs in physical properties from that previously reported for this compound.Evidence is provided for the structure of 9-O-demethylhomolycorine by 1H and 13C NMR studies.In the latter, the exploitation of long-range 1H coupling in the 13C spectra of lactones in this series is found to be diagnostically useful in assigning aromatic substitution patterns.A survey of the CD spectra of lactone alkaloids of the benzopyrano<3,4-g>indole system indicates that this technique can provide useful structural information.

Full text of DOI:10.1021/jo00210a031

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.