Diisobutylaluminum hydride → 3-(4-Methoxyphenyl)propanal

Participants

Reaction Steps

A solution of ester 12d (0.8346 g, 4.3 mmol) in 15 mL dry CH2Cl2 was cooled to -78° C. and treated with DIBAL (1.0M solution in dry CH2Cl2, 4.3 mL, 4.3 mmol, 1.0 equiv), upon completion by tlc the reaction was quenched immediately with 4.0 mL dry CH3OH. The reaction mixture was diluted with 15 mL saturated aqueous sodium potassium tartrate and warmed gradually to room temperature, partitioned, and extracted with CH2Cl2 (3×20 mL). The combined extracts were washed with saturated aqueous sodium potassium tartrate (3×25 mL), dried (MgSO4), filtered and concentrated in vacuo. SGC chromatotron (SiO2, 4 mm, 20-35% EtOAc/hexanes) afforded 13d (0.702 g, 0.706 g theoretical, 99%). For 13d: 1H NMR (CDCl3, 250 MHz) d 9.78 (d, 1H, J=1.4 Hz, CHO), 7.09 (d, 2H, J=8.6 Hz, Ar C2-H and C6-H), 6.82 (d, 2H, J=8.6 Hz, Ar C3-H and C5-H), 3.76 (s, 3H, OCH3), 2.87 (dd, 2H, J=6.9, 8.3 Hz, ArCH2), 2.72 (ddd, 2H, J=1.4, 6.9, 8.3 Hz, CH2 (C=O)); 13C NMR (CDCl3, 125 MHz) d 201.7, 158.0, 132.3, 129.1, 113.9, 55.1, 45.4, 27.2; IR (neat) nmax 2935, 2835, 1722, 1611, 1583, 1513, 1464, 1442, 1301, 1247, 1178, 1034, 831 cm-1. See FIG. 18h.

Provenance & Evidence