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.
Copper(I) mediated highly diastereoselective conjugate addition of Grignard reagents to functionalised cycloalkenols: a general and efficient route for the stereoselective synthesis of 5- and 6-membered ring trisubstituted cycloalkanols
The conjugateaddition of magnesium cuprates to various 2-silyloxycyclopentene and 2-silyloxycyclohexene carboxylates leads diastereoselectively to related syn–anti cyclopentanols and cyclohexanols in fair overall yields. The β-elimination occurring with free hydroxylic derivatives is also partially or totally avoided by concomitant in situ trapping of the generated enolates. Attempts to rationalise