Norio Tokutake

Alkane diols from flower petals of Carthamus tinctorius

Abstract Eleven novel secondary alkane-1,3-diols were isolated from a methanol extract of dried flower petals of Carthamus tinctorius . Their structures were determined to be syn ( R , S and/or S , R )-C 36 -alkane-6,8-diol, syn -C 28 -, C 30 -, C 32 , C 34 ,- and C 36 -alkane-7,9-diols, and syn -C 27 , C 29 -, C 31 -, C 33 - and C 35 -alkane-8,10-diols by spectral methods.

Stereochemistry of enantioselective deprotonation of 4-substituted cyclohexanones by chiral bidentate lithium amides

Abstract Enantioselective deprotonation of 4-substituted cyclohexanones (1) in the presence of excess trimethylsilyl chloride was examined using chiral bidentate lithium amides ((R)-3∼(R)-7) in THF. The solution structures of (R)-3a in THF in the presence and in the absence of lithium chloride were studied by NMR. It is concluded that the eight-membered cyclic transition state (10) offers reasonable explanation of the stereochemical course of the present reaction using (R)-3a.

The asymmetric favorskii rearrangement: A synthesis of optically active α-alkyl amides from aldehydes and (−)-1-chloroalkyl p-tolyl sulfoxide

Abstract The first asymmetric Favorskii rearrangement is described. Optically active α-alkyl amides of enantiomeric excess up to 94% were realized from aldehydes and optically active (−)-1-chloroalkyl p-tolyl sulfoxides via the Favorskii rearrangement of optically active α-chloro α-sulfonyl ketones.

Asymmetric Synthesis of Heptacosane-6,8-Diols Induced by Chiral Sulfoxides

Abstract The asymmetric synthesis of (6S,8R)-, (6S,8S)-, (6R,8S)- and (6R,8R)-heptacosane-6,8-diols from (2S)-, (2R)-1-[(R)-p-tolylsulfinyl]-2-heptanols and 1-icosanal is described.