7-hydroxy-3-(4-methoxyphenyl)-2H-1-benzopyran → Equol

HRID 254887Notes

Reaction equation

HRID 254887 reaction equation
[OH:1][C:2]1[CH:19]=[CH:18][C:5]2[CH:6]=[C:7]([C:10]3[CH:15]=[CH:14][C:13]([O:16]C)=[CH:12][CH:11]=3)[CH2:8][O:9][C:4]=2[CH:3]=1.[N+](CCCC)(CCCC)(CCCC)CCCC.[I-].B(Cl)(Cl)Cl>>[CH:11]1[C:10]([C@H:7]2[CH2:8][O:9][C:4]3[CH:3]=[C:2]([OH:1])[CH:19]=[CH:18][C:5]=3[CH2:6]2)=[CH:15][CH:14]=[C:13]([OH:16])[CH:12]=1

Participants

3

Reactant 2

HCID 98598477-hydroxy-3-(4-methoxyphenyl)-2H-1-benzopyranHCID 87695880n-Bu4NI BCl3

Product 1

HCID 91469Equol

Procedure

As shown in Scheme 2, 7-benzyloxy-3-(4-methoxyphenyl)-2H-1-benzopyran (compound 1) was reacted with n-Bu4NI/BCl3 and BCl3 to give haginin E (compound 2a) at a yield of 79% and 7-hydroxy-3-(4-methoxyphenyl)-2H-1-benzopyran (4′-O-methyl haginin E, compound 2b) at a yield of 81%, respectively. Treatment of compound 1 with Pd(OH)2/C (Pearlman's reagent) and cyclohexene in refluxing ethanol promoted O-debenzylation and reduction of the chromene ring in one step, giving 7-hydroxy-3-(4-methoxyphenyl)-1-benzopyran (compound 3a) at a yield of 94%. Compound 3a was subsequently demethylated by use of n-Bu4NI/BCl3 to give equol (compound 3b) at a yield of 95%.

Sources & evidence

ORD record
ord-01d837d32d524b5d9e34f5f9fc210ece
Source dataset
uspto-grants-2011_01
Patent number
US07875735B2

Reaction notes

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