After alpha,alpha'-dimetalation, both 2,2'-diallyloxy-1,1'-binaphthyl and 2,2'-di-2-methylallyloxy-1,1'-binaphthyl undergo the Wittig rearrangement with perfect diastereoselectivity. When racemic 1,1'-binaphthyl-2,2'-diol ("BINOL") is used as the starting material, it gives rise to a 1:1 mixture of antipodal stereoisomers, whereas enantiomerically pure (M)-2,2'-diallyloxy-1,1'-binaphthyl affords (M)-(S,S)-1,1-(1,1'-binaphthyl-2,2'-diyl)bis(2-propen-1-ol) as the sole product. The (M)-(S,S)/(P)-(R,R) mixture resulting from the rearrangement of racemic 2,2'-diallyloxy-1,1'-binaphthyl can be effectively subjected to a kinetic racemate resolution by applying the Sharpless-Katsuki asymmetric epoxidation. The single-sided Wittig rearrangement of 2-allyloxy-2'-propyloxy-1,1'-binaphthyl proceeds without any diastereoselectivity as this substrate can only be monometalated and hence is incapable of intramolecular aggregate formation which is instrumental for the observed stereoselectivity.

2005 Benzofuran derivatives R 0070 Heterosubstituted or Functionalized Derivatives of 1-and 2-(Trifluoromethyl)naphthalenes Emanating from Aryne Adducts. -Arynes, derived from starting compounds (I), undergo cycloaddition with furan (II) to give adducts (III) which are used for further derivatization. -(BAILLY, F.; COTTET, F.; SCHLOSSER*, M.; Synthesis 2005, 5, 791-797; Inst. Sci. Ing. Chim., Ec. Polytech. Fed. Lausanne, CH-1015 Lausanne, Switz.; Eng.) -K. Schneider 33-114

More than two dozen new CF 3 -substituted naphthalene derivatives were prepared in an expedient way by employing 3-and 4-(trifluoromethyl)benzyne as the key intermediates. 2-and 4-Chlorobenzotrifluoride were treated with butyllithium and the organometallic species thus generated were allowed to decompose in the presence of furan. The resulting cycloadducts 1 and 14 were reduced to the (trifluoromethyl)naphthalenes 2 and 15, ring-opened to the (trifluoromethyl)naphthols 3, 16 and 17 and transformed to the dibromo adducts 5 and 18. The latter were stereoselectively converted into the bromo-1,4-epoxy-1,4-dihydro(trifluoromethyl)naphthalenes 6, 7, 19 and 20 and, by deoxygenation, into various bromo(trifluoromethyl)naphthalenes 8, 9, 21 and 22. Trifluoromethyl substituted naphthoic acids 10-13 and 23-26 were obtained when the bromo compounds 6-9 and 19-22 were subjected to a halogen/metal permutation followed by carboxylation.

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