The Journal of Organic Chemistry

Stereochemistry of lithium dialkylamide-induced 1, 4-eliminations leading to substituted isobenzofurans

D Tobia, B Rickborn

Index: Tobia, David; Rickborn, Bruce Journal of Organic Chemistry, 1986 , vol. 51, # 20 p. 3849 - 3858

Full Text: HTML

Citation Number: 42

Abstract

The O-ethylation of 3-methyl-and 3-phenylphthalide followed by borohydride reduction was used to prepare cis/trans mixtures of 1, 3-dihydro-l-ethoxy-3-methyl (or pheny1) isobenzofuran. The cis isomer is formed preferentially, presumably due to steric interference of hydride attack by the 3-substituent. Equilibrium mixtures of the l-methoxy analogues, formed by acid-catalyzed transacetalization in methanol, slightly favor the trans isomer. ...