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
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.