Faculty Mentor: David Hunt
Student: Katrina Wunderlich
In our lab we wish to study the Brook Rearrangement on a series of aromatic silyl ketones. However, aromatic silyl ketones are not readily available commercially. Therefore, they must be synthesized. The current literature for the synthesis of silyl ketones tends to follow three basic steps:
1. Protection of aldehyde
2. Addition of TMS
3. Deprotection of ketone
Though the first two steps are largely straightforward, the deprotection in the third has proven more challenging. To date, literature suggests that the strategy most useful for the deprotection step largely relies on the use of mercury chloride which is toxic and expensive. In our lab, we’ve developed a synthesis to deprotect the ketone using an inexpensive and safe reagent known as oxone. The third step of this synthesis, the optimization of the conversion of the protected ketone to the deprotected ketone has been the focus of this study. Results indicate that heat hinders this conversion and increasing the molar ratio of oxone to starting material to 4:1 decreases the time necessary for deprotection. To date in our lab, we have been able to increase the GCMS percent yield of starting material to desired product from 20% to >99%. We have analyzed this synthesis strategy on F, Cl, Br, and OMe substituted benzaldehydes as well as trans-cinnamaldehyde and a heterocyclic derivative. Further characterization and purification of these compounds are necessary before they are used to study the Brook Rearrangement.