# Salvinorin B Meth­oxy­methyl Ether

 Title: Salvinorin B Meth­oxy­methyl Ether Author: Munro, Thomas A.; Ho, Douglas M.; Cohen, Bruce Michael Note: Order does not necessarily reflect citation order of authors. Citation: Munro, Thomas A., Douglas M. Ho, and Bruce Michael Cohen. 2012. Salvinorin B meth­oxy­methyl ether. Acta Crystallographica Section E: Structure Reports Online 68(Pt 11): o3225-o3226. Full Text & Related Files: 3515309.pdf (657.9Kb; PDF) Abstract: The title compound [MOM-SalB; systematic name: methyl (2S,4aR,6aR,7R,9S,10aS,10bR)-2-(3-fur­yl)-9-meth­oxy­meth­oxy-6a,10b-dimethyl-4,10-dioxo-2,4a,5,6,7,8,9,10a-octa­hydro-1H-benzo[f]isochromene-7-carboxyl­ate], $$C_{23}H_{30}O_8$$, is a deriv­ative of the κ-opioid salvinorin A with enhanced potency, selectivity, and duration of action. Superimposition of their crystal structures reveals, surprisingly, that the terminal C and O atoms of the MOM group overlap with the corresponding atoms in salvinorin A, which are separated by an additional bond. This counter-intuitive isosterism is possible because the MOM ether adopts the 'classic anomeric' conformation (gauche–gauche), tracing a helix around the planar acetate of salvinorin A. This overlap is not seen in the recently reported structure of the tetra­hydro­pyranyl ether, which is less potent. The classic anomeric conformation is strongly favoured in alk­oxy­methyl ethers, but not in substituted acetals, which may contribute to their reduced potency. This structure may prove useful in evaluating models of the activated $$\kappa$$-opioid receptor. Published Version: doi:10.1107/S1600536812043449 Other Sources: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3515309/pdf/ Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:11738405 Downloads of this work: