Chiral synthesis of 6,7-benzomorphans: Synthesis of ( -)1(S),2(S),4(R),6(R)-1,2,3,4,5,6-hexahydro-2,6-methano-8-methoxy -1,3,4,6-tetramethyl-3-benzazocine through the chromium hexacarbonyl mediated cyclisation of 1(S),1 ′(R)-1,2-dihydro-7-methoxy-1,4-dimethyl -1 (N-methy-N-trifluoroacetamido-1′-methylethan-2′-yl)naphthalene

Article abstract of DOI:10.1016/S0040-4020(01)86456-5

(-)1(S),2(S),4(R),6(R)-1,2,3,4,5,6-Hexahydro-2,6-methano-8-methoxy- 1,3,4,6-tetramethyl-3-benzazocine has been synthesised in 86 % enandomeric excess from the α-(v⁶-chromium tricarbonyl) complex of 1 (S), 1′(R)-1,2-dihydro-7-methoxy-1,4-dimethyl-1-(N-methyl-N-trifluoroacetamido- 1′-methylethan-2/-yl)naphthalene. A precursor of this compound is 2(R),4(,S)-4-(3-methoxyphenyl)-2,4-dimethylcyclohexanone which was obtained through an Enders' type C-methylation reaction of 4-(3-methoxyphenyl)4-methylcyclohexanone using SAMP as the reagent.