Diastereofacial selectivity in intermolecular nitrone cycloadditions to chiral allyl ethers. Application to Chiral Synthesis of Coniine
作者:Masayuki Ito、Masae Maeda、Chihiro Kibayashi
DOI:10.1016/0040-4039(92)80019-g
日期:1992.6
The intermolecular cycloadditions of a cyclic nitrone to chiral allyl ethers take place with erythro selectivity, where the degree of selectivity achieved is dependent upon the size of the alkyl substituent attached to the allylic chiral center, and these reactions are applied to the synthesis of optically active alkaloid coniine.
Chiral Preparation of (<i>R</i>)- and (<i>S</i>)-3-(Benzyloxy)-4,4-dimethyl-1-pentene
作者:Masayuki Ito、Chihiro Kibayashi
DOI:10.1055/s-1993-25817
日期:——
Facile routes for the preparation of an optically active allylic ether bearing the tert-butyl group at an allylic chiral center, i.e. 2-(benzyloxy)-3,3-dimethyl-1-pentene, in both (R)- and (S)-enantiomeric forms, which are expected to be promising, efficient dipolarophiles in highly stereoselective asymmetric nitrone cycloaddition, have been developed, utilizing commercially available L-tert-leucine and (R)-pantolactone, respectively, as chiral precursors.