S. Verma, M. N. Atanes, J. H. Busto
Feb 22, 2002
Citations
0
Influential Citations
13
Citations
Journal
The Journal of organic chemistry
Abstract
We report the enantiospecific synthesis of the sterically congested all-cis 2,3,4,5-substituted pyrrolidines 4, 5, and 6, from either D- or L-serine. Hemiaminal intermediate 13 is converted to the fully substituted pyrrolidine 15 by way of a tandem Wittig-Michael reaction. The endo stereochemistry of the C-3 methyl group of compound 15 is set by stereoselective reduction of the double bond in 11, driven by a preference for hydrogenation from the rear side of the molecule. The all-cis configuration of these fully substituted pyrrolidines has been established by X-ray analysis of compound 6. Removal of the benzenesulfonyl group from the highly substituted and functionalized intermediate 15 is successfully accomplished by sodium naphthalenide reduction.