Applications of bromolactones in synthesis. Stereospecific syntheses of cis-2-hydroxy-1-methylcyclohex-5-ene-1-carboxylic acid and related compounds

Abstract

cis-2-Hydroxy-1-methylcyclohex-5-ene-1-carboxylic acid (6; R = Me) is prepared in over 60% yield from the bromo-β-lactone (2; R = Me); attempted hydrolysis of the bromo-β-lactone (2; R = Me) gave the γ-isomer (3; R = Me), and lithium aluminium hydride reduction of both the bromo-β-lactone (2; R = Me) and the bromo-γ-lactone (3; R = Me) gave cis-2-hydroxymethyl-2-methylcyclohex-3-en-1-ol (8).