ORGN 138 |
| Three expedient methods for the synthesis of cyclopropyl and iodocyclopropyl alcohols with up to four contiguous stereogenic centers are reported. Route one involves asymmetric alkyl group addition to an enal followed by diastereoselective cyclopropanation. Route two parallels route one, except that iodoform is used to generate the zinc carbeniod and the products are iodocyclopropyl alcohols. Route three entails asymmetric vinylation of an aldehyde with alkylvinylzinc reagents and subsequent diastereoselective cyclopropanation. We also expand this methodology to synthesize vinyl cyclopropyl alcohols. After the asymmetric addition of dienyl groups to aldehydes in the presence of (-)-MIB, we furnish enantio- and diastereoenriched vinyl cyclopropyl alcohols through selective cyclopropanation at the double bond adjacent to the chiral center. Furthermore, synthesis of hetero atom (O, N) substituted cyclopropyl alcohols will also be reported. |
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Asymmetric Reactions and Syntheses, Metal-Mediated Reactions, Combinatorial, Parallel, and Solid-Phase Chemistry
8:00 PM-10:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Organic Chemistry |