Synthesis of α-fluoro-β, γ-alkenylphosphonates and conjugated fluoroenynes from a common intermediate (α-fluoropropargyl) phosphonate

✍ Scribed by Farid Benayoud; Ling Chen; George A. Moniz; Antonio J. Zapata; Gerald B. Hammond

• Book ID: 104208995
• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 817 KB
• Volume: 54
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(98)01017-5

✦ Synopsis

The efficient preparation of a-fluoro-~,y-alkenylphosphonate 3, via catalytic hydrogenation of (a-fluoropropargyl)phosphonate ester I, is described. Conjugated fluoroenynes 4 have been synthesized using a modified Homer Wadsworth Emmons (HWE) olefmstion of aldehydes or ketones and I in relatively good yields. Yields were lowered because of the formation of 0t-fluoro-yhydroxyallenylphosphonate S during the reaction. The nature of the counterion was very important in the outcome of the HWE reaction; better yields of fluoroenynes were obtained when a potassium base was used instead of a lithium base.