oxazolidinone-derived enoate 132 in the presence of 100 mol% of the chiral Lewis
acid, derived from MgI 2 and chiral ligand 138, afforded product 134 in excellent
yield and with high enantioselectivity. Lowering the catalyst loading significantly
reduced the yields but with similar levels of enantioselectivity. Conversion of 134
into the methyl ester using Otera’s protocol (Sm(OTf) 3 , MeOH), followed by
Scheme 24 Synthesis of dihydronepetalactone and its analog
Scheme 25 Synthesis of ricciocarpins A and B
Synthesis of Saturated Six-Membered Ring Lactones
111
acid, derived from MgI 2 and chiral ligand 138, afforded product 134 in excellent
yield and with high enantioselectivity. Lowering the catalyst loading significantly
reduced the yields but with similar levels of enantioselectivity. Conversion of 134
into the methyl ester using Otera’s protocol (Sm(OTf) 3 , MeOH), followed by
Scheme 24 Synthesis of dihydronepetalactone and its analog
Scheme 25 Synthesis of ricciocarpins A and B
Synthesis of Saturated Six-Membered Ring Lactones
111