NOVEL RING-CLEAVAGE BASED ON INTERMOLECULAR ALDOL CONDENSATION

Ring cleavage and reconstruction via intramolecular aldol condensation followed by Grob fragmentation under acetalization conditions (BF3/et hylene glycol) was developed into a novel ring cleavage based on inter molecular aldol condensation. On the basis of this reaction, (R,R)-3,5 -dimethylcyclohexanone was converted into the chiral straight-chain co mpound with syndiotactic methyl function. The ring cleavage reaction b ased on a crossed intermolecular aldol condensation was also examined, and the reaction pathway was discussed.