A convergent, highly stereoselective synthesis of a C-11-C-21 subunit of the macbecins
摘要:
Acetonide 20, a possible synthetic precursor of the macbecins, was prepared by a highly stereoselective route from the enantiomeric methyl 3-hydroxy-2-methylpropionates. A key step involved anti S(N)2' addition of Me2Cu(CN)Li2 to vinyloxirane 15 to effect stereoselective introduction of the allylic CH3 center and the Etrisubstituted double bond.