Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5225056 | Tetrahedron | 2007 | 9 Pages |
Abstract
Reaction of the laterally lithiated (S)-4-isopropyl-2-(2-methoxy-6-methylphenyl)oxazoline with p-tolualdehyde gave an inseparable mixture of the addition products in low diastereoselectivity. However, the (S,S)-product cyclized to the corresponding 3,4-dihydroisocoumarin faster than the (S,R)-product on silica gel, which allowed to be produced both enantiomers of 8-methoxy-3-(p-tolyl)-3,4-dihydroisocoumarin in moderate to good optical purity [S-enantiomer: 75% ee; R-enantiomer: 96% ee]. This procedure was applied to the short-step synthesis of optically active 3,4-dihydroisocoumarin natural products such as (R)-8-hydroxy-3-(1-tridecyl)-3,4-dihydroisocoumarin and (R)-phyllodulcin.
Graphical abstractDownload full-size image
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Katsuya Uchida, Tsutomu Fukuda, Masatomo Iwao,