I am working on synthesis of Z-11-hexadecenal, starting from 1,10-decandiol and monitoring the progress of different steps with TLC(n-hexane:ethyl acetate 9:1). But in some steps the products show very close Rf values. Does anyone have any experience on this subject? Any help you provide for this request will be appreciated.
To my understanding from your question you are performing a multi-step synthesis and you use the same solvent system for TLC for each step. For every new synthesis that you perform a different solvent system can be used for developing TLC. If for instance you have a three steps reaction the products 1,2 and 3 might have a different polarity therefore for every step an appropriate solvent system can be used. Try different solvent systems provided that for each reaction step you kept a reference sample (that is your starting material for each reaction).
You should provide more specific details for more advice, but Efstratios' answer is pretty good to cover the general process.
9:1 hex/EA is a fairly non-polar system and may not be suitable for all compounds.
Dear Efstratios,
I wanted to let you know how much I appreciated your help. You're Right! I'm performing a nine-step synthesis, But I have a reference article that have used 9:1 hex/EA as the solvent for purification by column chromatography for all steps. Worth noting that the products of reactions contain 16 carbons in almost chain structure, so it's not strange to use this nonpolar solvent as the eluent in column chromatography. This is the link of the article that I use as Reference:
Article Sex Pheromone of Lonomia obliqua: Daily Rhythm of Production...
I know that the best way to identify each step product is NMR. But in my country it's expensive due to sanctions of deuterated solvents. So I decided to ask help from who have any experience on synthesis of sex pheromones.
Best Regards,
Roya
Efstratios' answer is pretty good, generaly speaking.
Also we do not know what support you are using (silicagel, alumina...)
Sometimes, conditionning your supprt may be important (humidity, T°...)
Dear Dr. Bovy,
thank you for taking time out to answer my question.
I'm using silica gel TLC plates.
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