Cyclic triketone compounds and trimethylsilyoxy butadiene compounds and their use in the preparation of daunomycinone derivatives

Abstract

The invention provides novel cyclic triketone compounds of the formulae ##STR1## wherein S is H, alkyl or alkoxy and R* is a group of the formule ##STR2## wherein R.sup.1 is methyl and R.sub.2 is an alkyl group containing at least 2 carbon atoms or R.sup.1 is an alkyl group having 1-4 carbon atoms and R.sup.2 is an aryl group, a hetero aryl group, a --CH.sub.2 OR' group, a --CH.sub.2 N<group, a --CH.sub.2 SR" group or a --CH.sub.2 CH.dbd.CH.sub.2 group, wherein R' and R" are alkyl groups having 1-4 carbon atoms. These compounds can be used for preparing daunomycinone and derivatives thereof. Daunomycinone is used for preparing daunomycin and adriamycin. By introducing chirality at C-1 of ring A in the preparation of said novel compounds by using a novel diene of formula (1) in a Diels-Alder reaction for said preparation, the chirality of C-3 is established in the subsequent reaction with LiC.tbd.CSi(CH.sub.3).sub.3 in the synthesis of daunomycinone and deriviatives thereof. ##STR3## This last reaction leads to the desired compound wherein OH at C-3 and OR at C-1 are in the cis-position with respect to each other.

Dependencies are inferred from the claim text.