In a flame dried 100 ml Schlenk tube equipped with a magnetic stirring bar was placed 1c (0.6 g, 3.05 mmol) in 10 ml toluene. The solution was cooled to −78° C. and a 1.5M solution of DIBAL in toluene (4 ml, 6 mmol) was added dropwise along the wall of the vessel. Once the addition was complete, the reaction was allowed to stir at −78° C. for another hour at which point ESI MS showed the lack of starting material. MeOH was slowly added along the wall of the vessel at −78° C. The reaction mixture was then allowed to stir for 30 minutes while warming to room temperature. Saturated Na2SO4 was then added and the solution was allowed to stir for another 15 minutes. The reaction was then filtered and water and ether was added. The organic later was extracted from the partition three times, washed with brine, dried over Na2SO4 and concentrated under reduced pressure. The resulting white solid may be crystallized from EtOAc or MeOH to afford the title compound in 92% (428 mg) yield as a white solid. Silica column chromatography is not recommended. Mp=149-153° C. (decomp.) 1H NMR (CDCl3, 200 MHz) (δ: 7.66 (d, J=11.6 Hz, 1H), 7.23-7.18 (m, 2H), 7.02-6.94 (m, 4H), 5.48 (d, J=11.6 Hz, 1H), 3.27 (dd, J=7.0 Hz, 3.4 Hz, 1H), 2.99 (dd, J=9.0 Hz, 3.4 Hz), 2.90 (d, J=2.6 Hz, 1H), 2.75 (d, J=2.6 Hz, 1H), 1.17 (t, J=6.6 Hz, 1H) ppm. 13C NMR (CDCl3, 75 MHz) δ: 141.5, 121.4, 127.7, 127.3, 125.9, 125.1, 124.8, 124.6, 96.9, 94.4, 54.0, 41.5, 37.5, 32.5 ppm. HRMS (EI) of aldehyde monomer: 152.9561
