Benzyl Bromide → (+/-)-Benzyl 6-benzyloxy-2,5,7,8-tetramethylchroman-2-carboxylate

HRID 1531827Notes

Reaction equation

[CH3:1][C:2]1[C:3]([CH3:18])=[C:4]2[O:13][C:12]([C:15]([OH:17])=[O:16])([CH3:14])[CH2:11][CH2:10][C:5]2=[C:6]([CH3:9])[C:7]=1[OH:8].[H-].[Na+].[CH2:21](Br)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>CN(C=O)C>[CH2:21]([O:8][C:7]1[C:2]([CH3:1])=[C:3]([CH3:18])[C:4]2[O:13][C:12]([C:15]([O:17][CH2:1][C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=3)=[O:16])([CH3:14])[CH2:11][CH2:10][C:5]=2[C:6]=1[CH3:9])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of Trolox® (10 g, 39.1 mmol) at) at 0° C. in DMF (50 mL), was added sodium hydride (60% dispersion in oil, 3.5 g, 87.9 mmol). The reaction mixture was stirred at 0° C. for 15 minutes and then benzyl bromide (17.1 g, 99.9 mmol) was added drop wise. The reaction mixture was allowed to warm to room temperature and stirred for overnight. DMF was evaporated under high vacuum and then the residue was dissolved in ethyl acetate (200 mL) and washed with 1 N aqueous HCl (100 mL) and brine (100 mL) to give 10.1 g (58.7%) of an oil of the intermediate, benzyl (6-benzyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)carboxylate. 1H NMR (CDCl3) δ1.57 (s, 3H), 1.82 (m, 1H), 2.02 (s, 3H), 2.08 (s, 3H), 2.15 (s, 3H), 2.44 (m, 3H), 4.61 (s, 2H), 5.00 (q, 2H), 7.00-7.45 (m, 10H). MS(ES) m/z 431.

Workup

temperatureto warm to room temperature
stirringstirred for overnight
customDMF was evaporated under high vacuum
dissolutionthe residue was dissolved in ethyl acetate (200 mL)
washwashed with 1 N aqueous HCl (100 mL) and brine (100 mL)

Sources & evidence

ORD record: ord-aa4fdbee87864189b27ee0a00e1d7b60
Source dataset: uspto-grants-2001_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06200990B1

Reaction notes

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