Abstract
AbstractNitro‐substituted 1,3‐dioxanes and pyrans with potential biological activity were synthesized. The relative configurations of the threo and erythro isomers of 2‐nitro‐1‐phenylpropane‐1,3‐diol (the starting materials) and of 5‐nitro‐2,4‐diphenyl‐1,3‐dioxane, the products formed with benzaldehyde, were determined by 1H and 13C NMR spectroscopy. Cinnamaldehyde and nitroethanol give a homologue of nitrophenylpropanediol, which exists as a mixture of two diastereomeric cyclic hemiacetals. After dissolving in CDCl3, the ratio of these components changes from approximately 10:1 to 3:2 in a few days. The ethyl acetal of the hemiacetal is stereohomogeneous, and the ethoxy group is axial to the pyran ring owing to the anomeric effect. This configuration was proved by two‐dimensional NMR measurement, permitting separate observation of the originally overlapping multiplets and direct reading of the H,H coupling constants.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
