Journal article
Stereocontrol in Horner-Wadsworth-Emmons condensations of .alpha.-phosphono lactones with aldehydes: a synthesis of integerrinecic acid and senecic acid lactones
Journal of organic chemistry, Vol.58(22), pp.5967-5971
10/01/1993
DOI: 10.1021/jo00074a023
Abstract
The Horner-Wadsworth-Emmons condensations of α-phosphono lactones were investigated under a variety of conditions. Upon treatment with KHMDS and 18-crown-6 in THF, condensations of the five-membered ring phosphono lactones 7a and 8 with propionaldehyde afforded the E olefins cleanly. In contrast, these phosphonates gave predominantly the Z olefins upon treatment with propionaldehyde, K2CO3, and 18-crown-6 in THF. A similar, though somewhat less-pronounced trend was observed with the six-membered ring phosphono lactone 9a. However, in its condensation with acetaldehyde the more functionalized phosphono lactone 4 gave the best E selectivity (ca. 9:1) when DBU/CH3CN was used, providing the methyl ester of integerrinecic acid lactone (5) in 77% isolated yield. When K2CO3/18-crown-6/toluene was employed in a parallel reaction, only slight selectivity for the Z isomer was observed, but the methyl ester of senecic acid lactone (6) still was obtained in 43–46% yield from the product mixture. © 1993, American Chemical Society. All rights reserved.
Details
- Title: Subtitle
- Stereocontrol in Horner-Wadsworth-Emmons condensations of .alpha.-phosphono lactones with aldehydes: a synthesis of integerrinecic acid and senecic acid lactones
- Creators
- Koo LeeJohn A JacksonDavid F Wiemer
- Resource Type
- Journal article
- Publication Details
- Journal of organic chemistry, Vol.58(22), pp.5967-5971
- Publisher
- American Chemical Society
- DOI
- 10.1021/jo00074a023
- ISSN
- 0022-3263
- eISSN
- 1520-6904
- Language
- English
- Date published
- 10/01/1993
- Academic Unit
- Chemistry; Neuroscience and Pharmacology
- Record Identifier
- 9984216674502771
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