Abstract
Hydrolysis of 4,6-O-benzylidene-3-deoxy-3-C-(iodomethyl)-D-allal (1) in neutral buffered medium with or without silver ion assistance gives the cyclopropyl aldehyde 4 as the only product. Methanolysis of 1 gives an equal mixture of the α and β anomers of methyl 4,6-O-benzylidene-2,3-C-methylene-2,3-dideoxy-D-allopyranosides (6 and 7). These results indicate that the cyclopropylcarbinyl-oxo-carboniumion (2), is produced with unit efficiency in solvolyses in neutral media, and the formation of both diasteriomers (6 and 7) requires the complete absence of bicyclobutonium ion (9) resonance contribution to the stabilized intermediate, and implies a strong contribution from the oxo-carbonium ion 10. In basic media compound 1 undergoes quantitative dehydroiodination to the conjugated diene, 4,6-O-benzylidene-1,2,3-trideoxy-3-C-methylene-D-ribo-hex-1-enopyranose(8).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.