Ethyl bromoacetate → (+/-) ethyl (E)-4-[2-(5,6,7,8-tetrahydro-5,5-dimethyl-8-hydroxy-8-(carbethoxymethyl) naphthalen-2-yl)ethenyl]benzoate

HRID 1358

Reaction equation

HRID 1358 reaction equation
C1C2C(CC=CC=2)CCC1=O.C1C2C(=CC=CC=2)CCC1.[CH3:22][C:23]1([CH3:47])[CH2:32][CH2:31][C:30](=[O:33])[C:29]2[CH:28]=[C:27](/[CH:34]=[CH:35]/[C:36]3[CH:46]=[CH:45][C:39]([C:40]([O:42][CH2:43][CH3:44])=[O:41])=[CH:38][CH:37]=3)[CH:26]=[CH:25][C:24]1=2.Br[CH2:49][C:50]([O:52][CH2:53][CH3:54])=[O:51]>[Zn]>[CH3:47][C:23]1([CH3:22])[CH2:32][CH2:31][C:30]([OH:33])([CH2:49][C:50]([O:52][CH2:53][CH3:54])=[O:51])[C:29]2[CH:28]=[C:27](/[CH:34]=[CH:35]/[C:36]3[CH:37]=[CH:38][C:39]([C:40]([O:42][CH2:43][CH3:44])=[O:41])=[CH:45][CH:46]=3)[CH:26]=[CH:25][C:24]1=2

Participants

6

Reactant 4

HCID 7748Ethyl bromoacetateHCID 8404TetralinHCID 12069038Ethyl (E)-4-[2-(5,6,7,8-tetrahydro-5,5-dimethyl-8-oxo-2-naphthalenyl)ethenyl]-benzoate2×HCID 69540356Tetrahydronaphthalene-2-one

Product 1

HCID 20605993(+/-) ethyl (E)-4-[2-(5,6,7,8-tetrahydro-5,5-dimethyl-8-hydroxy-8-(carbethoxymethyl) naphthalen-2-yl)ethenyl]benzoate

Reagents, catalysts & solvents 1

HCID 23994ZincCatalyst

Procedure

Reaction Scheme 5 discloses another example for the preparation of compounds within the scope of Formula 3. In this example the substituent is introduced to replace the oxo function of tetrahydronaphthalene-2-one after the Z--Y(R2)--A--B group has already been coupled to the tetrahydronaphthalene nucleus. Thus, ethyl(E)-4-[2-(5,6-dihydro-5,5-dimethyl-naphthalen-8(7H)-one-2-yl)ethenyl]benzoate (Compound A2) is reacted with ethyl bromoacetate in the presence of zinc metal in a Reformatsky reaction to provide (±)ethyl (E)-4-[2-(5,6,7,8-tetrahydro-5,5-dimethyl-8-hydroxy-8-(carbethoxymethyl)naphthalen-2-yl)ethenyl]benzoate (Compound A32). Compound A32 is itself within the scope of the present invention, within the scope of Formula 1. Compound A32 is dehydrated, as shown in the example by treatment with (methoxycarbonyl sulfamoyl)triethylammonium hydroxide (Burgess reagent) to yield a mixture of ethyl(E)-4-[2-(5,6-dihydro-5,5-dimethyl-8-(carbethoxymethyl)naphthalen-2-yl)ethenyl]benzoate (Compound A33a), and ethyl(E)-4-[2-(5,6-dihydro-5,5-dimethyl-8(TH)-anti (carbethoxymethylidenyl)-naphthalen-2-yl)ethenyl]benzoate (Compound A33b). Compound A33a is within the scope of Formula 6, and Compound A33b is within the scope of Formula 3. ##STR20##

Workup

  1. customReaction Scheme 5

Sources & evidence

ORD record
ord-254a6649ca41404ba268a53b6dace89f
Source dataset
uspto-grants-1998_03
Patent number
US05723666

Linked notes

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