1. Reaction of bromoethane 1 and triphenylphosphine 2 give a compound 3. Treatment of this with abutyllithium, followed
Posted: Sun May 22, 2022 4:20 pm
1. Reaction of bromoethane 1 and triphenylphosphine 2 give a compound 3. Treatment of this with abutyllithium, followed by addition of aldehyde 4 gives a product 5 with the spectroscopic data listed below. Identify compounds 3 and 5, and draw mechanisms for their formation. Use the spectroscopic data to determine the exact structure of 5, and assign as fully as possible the signals reported. Explain how the NMR data allows you to assign the stereochemistry of the product. i) Buli Br + PPh3 3 5 1 2 ii) o 4 Compound 5: OH 5.35 (1H, da. J10, 6), 5.15 (1H, dd, J10, 4), 2.70 (1H, dsept. 17,4), 1.60 (3H, d, J6) 0.97 (6H, d, J7). SC 138.8 (CH), 121.5 (CH), 27.0 (CH), 22.7 (CH3), 14.0 (CH3). Vmax 1680 cm-1 mz 84, 69, 43. [25 marks]