10.07.2015 Views

Proceedings book download - 5Z.com

Proceedings book download - 5Z.com

Proceedings book download - 5Z.com

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Table 1. Synthesis of tetrahydro-β-carbolines via Pictet-Spengler ReactionAldehydeCHOProductNHOONHYield(%)AldehydeCHOProductYield(%)N73 H62NHOOCHONHOONHCHONH52NH67OOClCHONHClOONHNO 2CHOO 2NOON66 H64NHOMeOMeNO 2NO 2The distinguished peak for the stereo selective synthesis of product in 1 H- and 13 C-NMRspectra are related to the chemical shifts of H-1 and H-3 protons.O52.3OMeNHNH54.9O56.9OMeNHN 58.7HO56.8ONHNH58.6O57.3ONHNH59.1Scheme 3. Comparison of chemical shifts of the products with the synthetic cis- tetrahydroβ-carbolineisomers.The value of coupling constants and also chemical shifts could confirm the cis isomer asthe final product.The yields of products were between 52-73%. The products have thesuitable functional groups for carrying out the further reactions.In summary, we have found that the Pictet-Spengler reaction of tryptophan propargylesters with aromatic and heteroaromatic aldehydes generates cis-tetrahydro-β-carbolineswith stereoselectivity.This reaction tolerates all substituted phenyl derivatives that we triedfor aldehyde which means that this should be adaptable to a wide range of targets ofmedicinal synthetic interest.References1. Alberch, L., Bailey, P.D., Clingan, P.D., Mills, T.J., Price, R., Pritchard, R.G. Eur. J. Org. Chem.1887 (2004).2. Bailey, P.D., Beard, M.A., Phillips T.R. Tetahedron Lett. 50, 3645-3648 (2009).3. Sewgobind, N.V., Wanner, M.J., Ingemann, S., de Gelder, R., van Maarseveen, J.H., Hiemstra, H. J.Org. Chem. 73, 6405-6408 (2008).93

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!