LAH doesn't work on this particular compound.....only NaBH4 works, I see the reduction is done by TLC. I do the reaction in ethanol because that's what they use in the paper i found, but they don't give any supporting material on the experiment condition. so i found that you extinguish the reaction with water( because of the left over NaBH4, because it's added in excess). and that is how you get the ethanol/water mixture. If I put it directly to rotavapor, the temerature would have to be high, and my compund has a low boiling point too.
so i want to extract it from this mixture.
i tried CH2Cl2, and ether....they don't work so well.
i'l try ethyl acetate...if i do the reaction in methanol, what will change? methanol has a lower boiling point, but it's not jet low enugh....
I can only guess here, but this is what I think. Since you are not recovering your material and you haven't indicated its bp, if you are using a rotovap, there are two possibilities I would check. One, it is co-distilling with your solvents. (I don't think so if you are using tlc.) Another possibility and the one I prefer, since borohydride only slowly reduces esters, I don't think the reduction has gone to completion. I suspect it is going far enough to convince you that product has formed, but not necessarily to completion. Then, when you add water, this generates hydroxide. The hydroxide completes hydrolysis of remaining ester. The salt of the acid stays in the aqueous layer. Your extracts do not contain recovered ester to confirm completion of the reaction and you are concluding the problem is isolation of a volatile alcohol.
If you want to know and you have some of your alcohol, then switch to vpc for analysis and add an inert compound as an internal standard. If you weigh them out, you can calculate the percent yield of the reaction before work up.