Question

What reagent loses the alpha hydrogen to become the nucleophilic carbanion?

Aldol Reaction: Synthesis of trans, trans-1,5-Diphenyl-1,4. pentadien-3-one (Dibenzalacetone) In the present experiment, you will be performing a practical Aldol reaction using benzaldehyde acetone. The final condensed Aldol product (trans, trans-1,5-diphenyl-1,4-pentadien-3-one) an extensive conjugation system The first condensed Aldol benzaldehyde and acetone. The final condensed Aldol product will form when the initial Aldol product reacts with benzaldehyde resulting in 2:1 mole ratio of benzaldehyde and acetone. Addition Aldol products are initially formed, but then convert to condensed Aldol products. Recrystallization will be used to purify your product. Infrared spectroscopy and melting point will e used to characterize the and will have product will result with 1:1 mole ratio of final product trans,trans-1,3-diphenyl-1,4-pentadien-3-one OH +2HO Benzaldehyde Acetone M.W de/mL) MP.CO BPOO Refractive Index 106.1 1.042 Substanss Benzaldehyde 178 56 261 1.5463 1.3588 Acetone 581 0.791 trans-4-Phenyl-3-buten 146.2 42 2-one trans, trans-1,5-Diphenyl- 2343 113d 1,4-pentadien-3-one Aldol catalyst (3M Sodium hydroxide in 50/50 reagent alcohol/water) Reagent alcohol SAFETY PRECAUTIONS Safety goggles are required for performing this lab exercise Minimize the breathing of any vapors and skin contact of chemical reagents The Aldol catalyst is strongly basic. Wash any skin exposed to the Aldol catalyst Dispose chemical waste according to your instructor's directions Wash your hands thoroughly when the lab exercise has been completed 1. In a 5.0-mL, vial with a spin vane, place 2.0 mL. of fresh Aldol catalyst 2, while stirring in hood, add 300 μしof benzaldehyde and 100 μしof ACS-grade acetone into the 5-mL vial containing the Aldol catalyst. Seal vial and take to your lab area. 3. Stir the mixture strongly at room temperature for 25 minutes. (Solids should form in 45-60 seconds.) Revised July 2013 78

Answer 1