Bromhydrol → HCID 131711634, compound

HRID 426674Notes

Reaction equation

HRID 426674 reaction equation
[C:1]1(=[O:15])[C:6]2=[C:7]3[CH:14]=[CH:13][CH:12]=[CH:11][C@@H:8]3[CH2:9][O:10][C@@H:5]2[CH2:4][CH2:3][CH2:2]1.[Br-].[Al+3].[Br-].[Br-].[Cl-].[Al+3].[Cl-].[Cl-]>ClCCl>[C:1]1(=[O:15])[C:6]2=[C:7]3[CH:14]=[CH:13][CH:12]=[CH:11][C@H:8]3[CH2:9][O:10][C@@H:5]2[CH2:4][CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 166749BromhydrolHCID 6451240Aluminum(III) ChlorideHCID 131711635HCID 131711635, compound

Product 1

HCID 131711634HCID 131711634, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Reaction of a dl-cis-hexahydrodibenzopyranone prepared according to this invention with an aluminum halide such as aluminum bromide or aluminum chloride in a halogenated hydrocarbon solvent such as dichloromethane effects total epimerization to afford exclusively the corresponding dl-trans-hexahydrodibenzopyranone. As an example, dl-cis-1-hydroxy-3-(1,1-dimethylheptyl)-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-dibenzo[b,d]pyran-9-one, which is prepared in about 80 to about 85 percent yield in accordance with the process of this invention, can be reacted with about a 3 to 4 molar excess of aluminum chloride in dichloromethane at a temperature of about 25° C. to provide exclusively dl-trans-1-hydroxy-3-(1,1-dimethylheptyl)-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-dibenzo[b,d]pyran-9-one, i.e., nabilone. As noted hereinbefore, such trans-hexahydrodibenzopyranones are particularly useful in the treatment of anxiety and depression.

Workup

  1. customprepared

Sources & evidence

ORD record
ord-0bf02d74b44f45b2ae0d2243a8183be9
Source dataset
uspto-grants-1979_10
Patent number
US04171315

Reaction notes

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