3,4-dihydro-2H-pyran → HCID 66617162, compound

Participants

Reaction Steps

Under nitrogen atmosphere, 3,4-dihydro-2H-pyran (10.2 g, 121 mmol) was added dropwise to a stirred solution of 8-hydroxy-2,2,14,14-tetramethypentadecanedioic acid diethyl ester (16.1 g, 40 mmol) and p-toluenesulfonic acid monohydrate (catalytic amounts) in methylene chloride (100 mL) under cooling with an ice bath. The reaction mixture was allowed to warm to room temperature and stirred overnight. After the reaction was completed (TLC), the solution was filtered through basic aluminum oxide (50 g), which was washed with methylene chloride (4×30 mL). The filtrate was concentrated in vacuo to give crude product (19.5 g), which was purified by chromatography (silica gel, 200 g, heptanes/ethyl acetate=20:1, 10:1) yielding 2,2,14,14-tetramethyl-8-(tetrahydropyran-2-yloxy)-pentadecanedioic acid diethyl ester as a colorless oil (12.1 g, 62%). 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.69-4.59 (m, 1H), 4.11 (q, J=7.3 Hz, 4H), 3.98-3.82 (m, 1H), 3.65-3.40 (m, 2H), 2.00-1.18 (m, 26H), 1.24 (t, J=7.1 Hz, 6H), 1.15 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm): 177.74, 97.36, 76.48, 62.61, 60.02, 42.05, 40.70, 40.63, 34.90, 33.38, 31.16, 30.32, 30.26, 25.48, 25.10, 24.86, 19.96, 14.23.

Provenance & Evidence