Synthesis of PDE IVb Inhibitors. 1. Asymmetric Synthesis and Stereochemical Assignment of (+)- and (−)-7-[3-(Cyclopentyloxy)-4-methoxyphenyl]hexahydro-3H-pyrrolizin-3-one
Asymmetric synthesis of GlaxoSmithKline’s highly potent phosphodiesterase inhibitor 1 has been accomplished in nine steps and 16% overall yield. The original strategy suggested involves as a key step the silylation of enantiopure six-membered cyclic nitronates 4 obtained by a highly stereoselective...
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Published in | Journal of organic chemistry Vol. 76; no. 19; pp. 7893 - 7900 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English Russian |
Published |
WASHINGTON
American Chemical Society
07.10.2011
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | Asymmetric synthesis of GlaxoSmithKline’s highly potent phosphodiesterase inhibitor 1 has been accomplished in nine steps and 16% overall yield. The original strategy suggested involves as a key step the silylation of enantiopure six-membered cyclic nitronates 4 obtained by a highly stereoselective [4 + 2]-cycloaddition of an appropriate nitroalkene 5 to trans-1-phenyl-2-(vinyloxy)cyclohexane. Functionalization of the resulting 5,6-dihydro-4H-1,2-oxazine and subsequent stereoselective reduction of 1,2-oxazine ring in intermediate 2 furnished the pyrrolizidinone framework with the recovery of chiral auxiliary alcohol. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/jo201331h |