Abstract
Nonracemic and 18O-labeled 4-tosyloxyprotoadamantane-4-carbonitriles 10c, 11c were prepared. In 60 % dioxane, the exo-OTs isomer 10c afforded ca. 97% of 2-tosyloxyadamantane-1-carbonitrile (14) with ee = 98% and with 23% equilibration of the tosylate oxygen atoms. The data point to a tight ion pair which undergoes nearly complete and stereospecific recombination. The endo-OTs isomer 11c underwent internal return to give endo-4-tosyloxyprotoadamantane-3-carbonitrile (20, 60% yield, 51% equilibration of the tosylate oxygen atoms), elimination (6%), and solvolysis (34%) competitively. 2-Hydroxyadamantane-1-carbonitrile (15) and 4-hydroxyprotoadamantane-3-carbonitrile (exo/endo = 18/22 ≈ 2.8) were formed with ee ≥ 97%. According to these results, the chirality (unsymmetrical bridging) of the parent 2-adamantyl cation is not detectably affected by 1-CN whereas the endo selectivity of the parent 4-protoadamantyl cation (symmetrical bridging) is eliminated by 3-CN.
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.
