Tetsutaro Hattori

Highly stereospecific conversion of planar chirality of a cyclophane into axial chirality of binaphthyls

Abstract Reaction of oxanaphthalenophane (R)- 2 with 1-naphthyl Grignard reagents 3 affords 1,1′-binaphthyls 4 of high enantiomeric purity, providing the first example of an asymmetric ring-opening of the cyclophane class of compounds. Because the stereoselectivity of the reaction coincides very well with that of the reaction of (−)-menthyl ether 1 with 3 , which we reported previously, it is supposed that the steric effect of the (−)-menthoxy moiety of 1 is equivalent to that of the ansa chain of (R)- 2 in these reactions.

1,12-Dioxa[12](1,4)naphthalenophane-14-carboxylic acid: practical synthesis, resolution and absolute configuration of the enantiomers

Abstract A novel naphthalenophane, 1,12-dioxa[12](1,4)naphthalenophane-14-carboxylic acid ( 1 ), is conveniently prepared from 1,4-dihydroxy-2-naphthoic acid and 1,10-dibromodecane. Acid 1 is resolved by crystallization of its quinine or quinidine salt, and the absolute stereochemistry of acid (−)- 1 is determined to be S by the X-ray crystallographic analysis of (1 S ,2 R ,4 R )-(−)-2,10-camphorsultam) amide derivative ( 4 ).

REACTION OF BENZOIC ESTERS WITH ORGANOLITHIUM AND -MAGNESIUM REAGENTS. DICHOTOMY BETWEEN NUCLEOPHILIC AROMATIC SUBSTITUTION AND CONJUGATE ADDITION

Abstract The reactions of 2,6-di-tert-butyl-4-methoxyphenyl 2-methoxybenzoate 1a with several organolithium and -magnesium reagents are found to give the methoxy-substitution products 2 and/or the conjugate addition products to the benzoate ring ( 3 and 4 ), preferring the latter products at the expense of the former with the increase of the electron-donating ability of the carbonion species. A SET mechanism is proposed for the conjugate addition.

Facile construction of the 1-phenylnaphthyl skeleton via an ester-mediated nucleophilic aromatic substitution reaction. Applications to the synthesis of phenylnaphthalide lignans

A convenient method is presented for the construction of the 1-phenylnaphthyl skeleton via an ester-mediated nucleophilic displacement of a methoxy group from an aromatic nucleus by Grignard nucleophiles. Thus, treatment of isopropyl 1-methoxy-2-naphthoate 1 with a phenyl Grignard reagent 2 or 8 affords the 1-phenyl-2-naphthoate ester 3 or 9 in good to excellent yield. Similarly, treatment of a 2,6-dialkylphenyl 2-methoxybenzoate 4b or c with a 1-naphthyl Grignard reagent 5 gives the 2-(1-naphthyl)benzoate ester 7. The methodology has been utilized in the synthesis of the naturally occurring phenylnaphthalide lignans, taiwanin C 12a and chinensin 12b.

Nucleophilic aromatic substitution of 2-sulfonyl-substituted 1-methoxynaphthalenes with Grignard reagents

2-Alkylsulfonyl, -phenoxysulfonyl or -sulfamoyl substituted 1-methoxynaphthalenes 1 undergo nucleophilic displacement of the 1-methoxy group when treated with Grignard reagents; the chiral sulfamoyl-substituted naphthalene 1f on treatment with the 2-methoxy-1-naphthyl Grignard reagent 2d induced axial chirality to give the 1,1′-binaphthyl 3fd in 80% diastereoisomeric excess (de).