Chroman-8-carbaldehyde, 95%

Step B - Synthesis of Compound 21 C; To a solution of compound 21B (10.9 g, 29.23 mmol) in dry THF (240 mL) and hexanes (40 mL) under anhydrous atmosphere at -78 0C, was added n-butyl lithium (20 mL of a 2.5M solution in toluene) dropwise. During the addition, the internal temperature of the solution was kept below 5 0C. The reaction mixture was stirred at approx. 5 °C for 4 hours before a slow addition of additional n-butyl lithium (5.8 mL of a 2.5M solution in toluene diluted into 20 ml hexanes). The resulting mixture was stirred at 5 0C for 0.5 hours, followed by an addition of a solution of dimethyl formamide (3.38 mL, 43.84 mmol) in 10 mL of THF. The reaction mixture was stirred at 5 °C for 10 minutes, then was warmed to room temperature and stirred for an additional 0.5 hours, and quenched with aqueous 1 N HCl solution (100 mL). The layers were separated, and the aqueous layer was extracted with ether (3 x 200 mL). The combined organic layers were washed with brine (100 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. The resulting residue was purified by column chromatography using a Biotage 75-M silica gel column (gradient: 0 to 20 percent ethyl acetate in hexanes) to provide compound 21C (4.20 g, 88 percent). 1H NMR (400 MHz, CDC13): δ 10.41 (s, IH), 7.64 7.63 (dd, J= 1.5 Hz, 8.1 Hz, IH), 7.25 (d, J= 5.13 Hz, IH), 6.89 (t, J= 7.3 Hz, IH), 4.30 (t, J= 5.1 Hz, 2H), 2.83 (t, J= 6.2 Hz, 2H), 2.09 - 2.03 (m, 2H).8-Chromanylacetic acid can be prepared in three stages from chroman, with an overall yield of 60percent, as illustrated by Synth. Comm., 12, 763-70 (1982).

Molecular Weight:162.18
XLogP3:1.7
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:162.068079557
Monoisotopic Mass:162.068079557
Topological Polar Surface Area:26.3
Heavy Atom Count:12
Complexity:167
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes