3-Methylcyclohex-2-enone derivatives as initiators of cyclisation. Part 2. Monocyclisations to six-membered rings
作者:Joseph A. Amupitan、Enamul Huq、Michael Mellor、Edward G. Scovell、James K. Sutherland
DOI:10.1039/p19830000751
日期:——
Cyclisation of 3-methylcyclohex-2-enones and the derived epoxides containing alkene, alkyne, and aryl side-chains yields bicyclo[4.4.0]decane derivatives when the alkene or alkyne is electronically biased towards six-memberedring formation and when the alkene is electronically unbiased.
10-Methyl-cis-9-decalinols are important motifs in several natural products and key intermediates in total synthesis. Herein, we wish to describe a highly chemo- and diastereoselective cyclization of ketoepoxides leading to 10-methyl-cis-9-decalinols. This method based on the use of zirconium(IV) tetrachloride permits the access to a wide variety of cis-decalinols in good to excellent yields. The cationic cyclization could also be performed with chiral keto-epoxide with complete control of the diastereoselectivity affording cis-bicyclic tertiary alcohol with good enantiomeric excess. The chemo- and the diastereoselectivity are assumed to result from the ability of Zr(IV) to generate highly stable bidentic complexes with alpha-hydroxy-ketone intermediates. (C) 2011 Elsevier Ltd. All rights reserved.
AMUPITAN, J. A.;HUQ, E.;MELLOR, M.;SCOVELL, E. G.;SUTHERLAND, J. K., J. CHEM. SOC. PERKIN TRANS., 1983, N 4, 747-749
作者:AMUPITAN, J. A.、HUQ, E.、MELLOR, M.、SCOVELL, E. G.、SUTHERLAND, J. K.