4-Methyl-1-pentene → 3-Benzyloxy-7-(4-methyl-pentyl)-2-(3,4,5-trimethoxy-phenyl)-chromen-4-one

Participants

Reaction Steps

To a stirring solution of 4-methyl pent-1-ene (0.110 g, 1.3 mmol, 1.4 eq) in tetrahydrofuran (2 ml) under argon at 0° C. was added 9-BBN in tetrahydrofuran (0.5M, 2.7 ml, 1.4 mmol, 1.5 eq). The reaction was allowed to warm to room temperature then stirred for 6 hours then 34 (0.499 g, 0.9 mmol) (prepared as described in Example 2) in tetrahydrofuran (5 ml), 3M NaOH solution (1.1 ml) and dichloropalladium (dppf) (0.028 g, 0.03 mmol, 0.04 eq) were added and the reaction heated to reflux for 14 hours. The reaction was then quenched with water and diethyl ether. The organic layer was collected and the aqueous layer extracted with diethyl ether (2×). The combined organic layers were washed with 1M HCl and brine then dried (MgSO4) and concentrated in vacuo to give a yellow oil. A silica plug (dichloromethane) yielded 39e* (0.197 g, 49%) as a yellow oil.

Provenance & Evidence