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Phenolic hydroxyl in Horner Wadsworth Emmons reaction
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Babcock_Hall:
https://www.cell.com/cell-chemical-biology/pdf/S1074-5521(98)90169-7.pdf
Bogyo and collaborators (Chemistry & Biology June 1998, 5:307-320) used a diethyl sulfonylphosphonate which had a phenol group on sulfur in a Horner reaction. The phenolic -OH was not protected. The substrate was a peptide aldehyde, and the base was NaH. This paper cites a 1997 paper for the reaction conditions, but the 1997 paper does not provide a detailed protocol. I am thinking about trying a reaction in which the aldehyde would have an unprotected hydroxypyridine group, and I am wondering whether the reaction above is a relevant precedent. Both the ideal choice of the base and the number of equivalents are of interest.
Babcock_Hall:
I neglected to explain a few things in my previous comment. The hydroxyl group was para with respect to the sulfonyl group in the paper I cited in my previous comment. We are attempting to synthesize a vinyl sulfone from 3-hydroxyisonicotinaldehyde. Although we were able to get a low but acceptable yield using an isomeric aldehyde in a Knoevenagel reaction, we have only obtained a few milligrams of the product with this aldehyde, which is not enough for our collaborators to use. That is why we are considering using a Horner Wadsworth Emmons reaction.
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