Copper (I) mediated highly diastereoselective conjugate addition of Grignard reagents to functionalised 6-membered ring cycloalkenols. Synthesis of cyclohexanes derivatives substituted on three contiguous atoms
Copper catalysed conjugateaddition of Grignard reagents to 2-silyloxycyclohexene carboxylates in the presence of an excess chlorotrimethylsilane, leads diastereoselectively to related (anti) (Z) silylketene acetals. Subsequent hydrolysis and desilylation afford 2-hydroxycyclohexane carboxylates in high yields and diastereoselectivities.