Triphenylphosphine → Ethyl-p-((E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-1-propenyl)benzoate

HRID 1447501Notes

Reaction equation

HRID 1447501 reaction equation
P(Br)(Br)Br.BrCCC1C2C(C)(C)CCC(C)(C)C=2C=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[Br-].[CH3:42][C:43]1([CH3:76])[CH2:52][CH2:51][C:50]([CH3:54])([CH3:53])[C:49]2[CH:48]=[C:47]([CH:55]([P+](C3C=CC=CC=3)(C3C=CC=CC=3)C3C=CC=CC=3)[CH3:56])[CH:46]=[CH:45][C:44]1=2.[CH2:77]([O:79][C:80]([C:82]1[CH:89]=[CH:88][C:85]([CH:86]=O)=[CH:84][CH:83]=1)=[O:81])[CH3:78]>CCOCC.CCCCCC.C1(C)C(C)=CC=CC=1.N1C=CC=CC=1>[CH2:77]([O:79][C:80](=[O:81])[C:82]1[CH:89]=[CH:88][C:85](/[CH:86]=[C:55](/[C:47]2[CH:46]=[CH:45][C:44]3[C:43]([CH3:76])([CH3:42])[CH2:52][CH2:51][C:50]([CH3:53])([CH3:54])[C:49]=3[CH:48]=2)\[CH3:56])=[CH:84][CH:83]=1)[CH3:78]

Participants

9

Reactant 5

HCID 11776TriphenylphosphineHCID 24614Phosphorus tribromideHCID 80498Ethyl 4-formylbenzoateHCID 11238302Triphenyl(1-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)ethyl)phosphonium bromideHCID 205510462-Bromoethyl-5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-naphthalene

Product 1

HCID 6437076Ethyl-p-((E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-1-propenyl)benzoate

Reagents, catalysts & solvents 3

HCID 1049PyridineSolventHCID 7237O-XyleneSolventHCID 21584099Diethylether hexaneSolvent

Procedure

5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-naphthalene is reacted with acetyl chloride and aluminium chloride in nitrobenzene to give (5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl) methyl ketone. Reduction of this ketone with lithium aluminium hydride in ether yields 5,6,7,8-tetrahydro-α-5,5,8,8-pentamethyl-2-naphthalene-methanol which is converted by treatment with phosphorus tribromide in ether/hexane in the presence of a small amount of pyridine into 2-bromoethyl-5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-naphthalene. This bromoethyl compound is converted by treatment with triphenylphosphine in xylene while heating for 12 hours into [1-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-ethyl]-triphenylphosphonium bromide which, in a Wittig reaction with 4-ethoxycarbonyl-benzaldehyde, yields p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-propenyl]-benzoic acid ethyl ester of melting point 90°-91° C. This ester is reduced with lithium aluminum hydride in ether/tetrahydrofuran to give p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-propenyl]-benzyl alcohol of melting point 123°-124° C. (from methanol).

Sources & evidence

ORD record
ord-29eb1aa85d3e42c0be417255a65f17b5
Source dataset
uspto-grants-1982_02
Patent number
US04316983

Reaction notes

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