Talk:Appel reaction

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I do not quite see the double displacement reaction in this reaction but I would expect reference to SN2 reaction with Walden inversion am I missing a point? rikXL 22:40, 16 Jun 2005 (UTC)

:Going from 4 to 6/7 you do indeed do a double displacement of sorts- you react RCH2-O⁻ with +P-Cl and get +P-O⁻ and RCH2-Cl (the O⁻ and Cl have swapped places). The P=O resonance form is shown so it's perhaps less obvious. However the second step of that sequence, 5 going to 6/7 is indeed just an SN2 reaction, perhaps worth mentioning. Does the reaction work with secondary alcohols too (so you could see Walden inversion easily)? If so, that would be worth commenting on in the article, as only primary alkyl is shown in the scheme. Also, I should mention that I think the ratio of font size to bond length in the basic reaction scheme looks unsightly- I think the atom labels should be much smaller. The mechanism by contrast is beautifully done. Walkerma 04:58, 19 Jun 2005 (UTC)

::I added some text to clarify the "double displacement" statement I made. It should be more clear now. Yes, the reaction works with secondary alcohols, and a SN2 and Walden inversion do take place with them. Ironically, the same ChemDraw settings were used for the top image as the mechanism image. I agree a little bit about the unsightliness of the top image, so I made it slightly smaller. It looks a little better. If it really bugs me, I'll draw a new one. (Feel free to substitute it with one of your own if it really bugs you.) ~K 18:04, 19 Jun 2005 (UTC)

1. Duing the displacement reaction of halide ion by PPh3(first step of mechanism), the attack of lone pair of PPh3 on hlide how is possible? Because the electronegativity of carbon is 2.5 whereas 2.96 for bromide. That means carbon is more electrophile compare to bromine. I can not understand that point. anyone can explain that point plz...............sumanta(sum_bbn@yahoo.co.in) —Preceding unsigned comment added by 59.163.216.16 (talk) 17:56, 14 July 2009 (UTC)