ORGN 887 |
| There have been numerous applications of transition-metal catalyzed cycloisomerization reactions involving 1,6- and 1,7-enynes for the synthesis of cyclopentyl and cyclohexyl ring systems. However, simple 1,5-enynes and other skeletal derivatives have yet to be used as viable starting materials for these rearrangements. These unsaturated systems were elaborated to give a variety of cyclic and non-cyclic products via Au-(I) catalysis. All carbon 1,5 enynes, when subjected to Au-(I) catalysis, afforded bicyclo[3.1.0]-hexenes in good yield. Subsequent 4-hydroxy-1,5-enynes undergo an oxy-Cope rearrangement to afford &alpha,&beta-unsaturated ketones. 1,5-enynes containing a silicon atom instead of carbon at the propargylic position can undergo nucleophilic attack by an external nucleophile to afford substituted vinylsilanes, which are useful cross-coupling partners.
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New Reactions and Methodology
8:00 AM-11:40 AM, Thursday, 14 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |