Base-induced cyclisations of naphthalenes into naphtho[2,3-c]pyrans. Application to stereospecific syntheses of (±)-isoeleutherin and (±)-deoxyquinone a dimethyl ether
Abstract
2-(Alk-2-enyl)-3-(1-hydroxyalkyl)-1,4-dimethoxynaphthalenes are cyclised and then oxidised to naphtho[2,3-c]pyran-5,10-quinones which are naturally occurring quinones or their derivatives.