8-Methoxy-4,7-dimethylchroman-2-one
THF (distilled sodium/benzophenone)
Diisobutylaluminium hydride (1.0 M in Hexane, Acros)
Magnesium sulfate (BDH)

To a precooled (-78^oC) solution of 8-Methoxy-4, 7-dimethylchroman-2-one (4.0 g, 19 mmol) in THF (150 mL) was added diisobutylaluminium hydride (23 mL, 23 mmol) dropwise over 10 minutes and the resulting clear solution stirred at -78^oC for 3h. Water (5 mL) was added dropwise and the solution allowed to warm to RT. Magnesium sulfate (ca. 15 g) was added and the suspension was filtered and the filtrate concentrated in vacuo. The crude residue was purified by flash column chromatography (20-50% ether/petroleum ether 40-60^oC) to yield firstly 8-methoxy-4, 7-dimethylchroman-2-ol as a viscous clear oil (3.2 g, 15 mmol, 82%) then 3-(2-hydroxy-3-methoxy-4-methylphenyl)-butan-1-ol as a white solid (0.6 g, 4.0 mmol, 18%). Product lactol is a 3 : 1 mixture of diastereoisomers.

Major isomer: (¹H NMR, CDCl₃) 6.83 (1H, ArH), 6.72 (1H, ArH), 5.72 (1H, OCHO), 4.09 (1H, OH), 3.71 (s, OCH₃), 3.15 (1H, ArCH), 2.25 (3H, ArCH₃), 2.14-2.00 (1H, CH₂), 1.79-1.64 (1H, CH₂), 1.24 (3H, CH₃). Minor isomer: 6.78 (1H, ArH), 6.72 (1H, ArH), 5.57 (1H, OCHO), 4.19 (1H, OH), 3.73 (s, OCH₃), 2.94 (1H, CH), 2.25(3H, ArCH₃), 2.14-2.00 (1H, CH₂), 1.79-1.64 (1H, CH₂), 1.29 (3H, CH₃).

D.C. Harrowven, J.D. Wilden, M.J. Tyte, M.B. Hursthouse, S.J. Coles, Tetrahedron Letters, 2001, 42, 1193