Reaction of Zinc Enolates Prepared from 2,2-Dibromoindan-1-one or 2,2-Dibromo-1-tetralone and Zinc with 2-Oxochromen-3-carboxylic Acid Derivatives

摘要

Zinc enolates obtained from 2,2-dibromoindan-l-one or 2,2-dibromo-l-tetralone and zinc reacted with alkyl esters and amides of 2-oxochromen-3-carboxylic acid giving the corresponding derivatives of 2,l'-dioxo-spiro(1a,7b-dihydrocyclopropa[c]chromen-1,2'-indan)-or 1 ',2',3',4'-tetrahydro-2,1'-dioxospiro(1a,7b-dihydro-cyclopropa[c]chromen-l,2'-naphthalene)-la-carboxylic acids prevailingly in the form of a single geometric isomer.