ORGN 470 |
| Scott B. Lewis, Jenny L. Muth, and Nikole D. Morrow. Department of Chemistry, James Madison University, MSC 7701, Harrisonburg, VA 22807 |
| Previous studies with symmetric 1,2-disubstituted cyclobutenes in reactions with difluorocarbene have shown that they will produce the 1,3-difluoroaromatic motif in one pot in up to 77% yields. The synthesis of asymmetric compounds such as 1-phenyl-2-methylcyclobutene (1) and 1-butylcyclobutene (2) were undertaken in order to further study this novel approach to 1,3-difluoroaromatics. Reactions involving compounds 1 and 2 using Ph-Hg-CF3 have shown remarkable regioselectivity giving isomer ratios as high as 84:16 in the product 1,3-difluoroaromatics. Further, the major isomer formed when Ph-Hg-CF3 is used appears to be formed from a radical cation like intermediate, not a fully cationic intermediate as previously believed. Reactions of compound 2 using sodium chlorodifluoroacetate as the difluorocarbene source produced a nearly 50:50 ratio of the two possible 1,3-difluoroaromatic products. |
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Total Synthesis, Asymmetric Reactions and Syntheses, Bioorganic
9:00 AM-11:00 AM, Wednesday, March 31, 2004 Anaheim Convention Center -- Hall C, Poster
Division of Organic Chemistry |