Acetyl chloride → 1-(5,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)ethan-1-one

HRID 1447500Notes

Reaction equation

HRID 1447500 reaction equation
[CH3:1][C:2]1([CH3:14])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]2[CH:7]=[CH:6][CH:5]=[CH:4][C:3]1=2.[C:15](Cl)(=[O:17])[CH3:16].[Cl-].[Al+3].[Cl-].[Cl-]>[N+](C1C=CC=CC=1)([O-])=O>[CH3:16][C:15]([C:6]1[CH:5]=[CH:4][C:3]2[C:2]([CH3:14])([CH3:1])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]=2[CH:7]=1)=[O:17]

Participants

5

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-253bebd7ab844273b773b655f121e731
Source dataset
uspto-grants-1982_02
Patent number
US04316983

Reaction notes

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