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13th October 2016 @ 20:02

Started 10/4


 Based on AEW 221-2.


Dried 3-necked round bottom flask+stir bar on high-vacuum w/ heat gun. Immediately placed under Argon. (attempting to conduct reaction under anhydrous conditions)

Transferred LiAlH4 (about 0.5 g) to the round bottom flask. Added 12 mL Et2O (anhydrous) via syringe. Stirred in ice bath (~0 C).

Dissolved MRLS 6-1 (4.57 g, 18.26 mmol) in anhydrous Et2O (8 mL). Transferred this mixture to the LiAlH4 suspension via syringe. Added dropwise over ~5 minutes. Stirred in ice bath for about 1 hour. Removed the round bottom from the ice bath and stirred at room temperature for 3 hours. Then, refluxed the mixture for about 16 hours. 


Quenched the LAH by stirring with rochelle salts and Et2O overnight.


Filtered the reaction mixture through celite. Washed round bottom with EtOAc. Performed extraction (3x30 mL EtOAc) of the mixture, and combined the organic layers. Dried the layers with sodium sulfate, followed by gravity filtration and rotovap. Yield: 3.39 g, 83.5%. Took NMR of the crude.


Attempted to purify the crude with the Biotage Isolera. 

Used KP-Sil 100 g column. Loaded sample by dissolving in DCM, adding silica gel, and then rotovap (dry loading instead of using a samplet). Unfortunately, had issue with attaching solvent lines to the column, resulting in a spill (possibly affecting sample?). Collected 6 fractions.


Rotovapped fractions. Although I had expected the product to be in the second fraction, there was almost no product after rotovapping. The other fractions, however, did have some product (test tubes 20-29 and 30-40).



Took proton NMR of fractions 20-29 and 30-40. Ethyl acetate solvent impurities near 1.25 ppm (t), 2.03 ppm (s), 4.11 ppm (q). Will attempt to run NMR again after removing solvents.

Redid NMR (removed EtOAc/Hexanes by rotovapping CDCl3 mixture, then adding CDCl3, rotovapping once more, and then dissolving that sample in CDCl3). Attached below. The NMRs seem to be very similar, but unsure why there are differences. I will try asking for assistance on our GitHub post (issue #430).


It seems like the fractions are diastereomers of one another (thanks to Chase Smith (@MedChemProf) for his help here!) .


I've also added GC-MS results (TIC and MS) for both fractions. The mass peak matches that of the structure above with a cleaved CH2OH (M+ of ~191).



Attached Files
8-1 fraction 1 13C NMR
8-1 fraction 2 13C NMR
8-1 fraction 2 1H NMR
8-1 fraction 1 1H NMR
8-1 GCMS (frac 1)
8-1 GCMS frac 2
Re: Synthesis of 2-phenyl-2-((tetrahydro-2H-pyran-2-yl)oxy)ethan-1-ol (MRLS 8-1) by Mandrake Fernflower
13th October 2016 @ 21:10
Anyluck with the product recovery? If for whatever reason you cannot produce the alcohol you could always couple the nemesis core to 2-phenylethanol
Re: Synthesis of 2-phenyl-2-((tetrahydro-2H-pyran-2-yl)oxy)ethan-1-ol (MRLS 8-1) by Marco Rivas
14th October 2016 @ 20:50
Hi, thanks for the suggestion!

I recently was able to rotovap the other fractions, and managed to isolate something in those. I took NMR of some of these (although the samples seem to contain some solvent impurities from ethylacetate/hexane). I will try running a cleaner NMR later tonight before I say for sure whether I isolated the right product.

Will keep the post updated,