Methanol → Arotinoic methanol
Reaction equation
C([O:3][C:4](=O)[C:5]1[CH:10]=[CH:9][C:8](/[CH:11]=[C:12](/[C:14]2[CH:23]=[CH:22][C:21]3[C:20]([CH3:25])([CH3:24])[CH2:19][CH2:18][C:17]([CH3:27])([CH3:26])[C:16]=3[CH:15]=2)\[CH3:13])=[CH:7][CH:6]=1)C.[H-].[Al+3].[Li+].[H-].[H-].[H-].CO>CCOCC.O1CCCC1>[CH3:24][C:20]1([CH3:25])[CH2:19][CH2:18][C:17]([CH3:26])([CH3:27])[C:16]2[CH:15]=[C:14](/[C:12](/[CH3:13])=[CH:11]/[C:8]3[CH:9]=[CH:10][C:5]([CH2:4][OH:3])=[CH:6][CH:7]=3)[CH:23]=[CH:22][C:21]1=2Participants
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-ba7cb043e01743109ad6d336ae167255
- Source dataset
- uspto-grants-1982_02
- Patent number
- US04316983
Reaction notes
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