Highly enantio- and diastereoselective Brassard type hetero-Diels-Alder approach to 5-methyl-containing alpha,beta-unsaturated delta-lactones.
Two efficient new chiral copper (II) Schiff base complexes were developed for the highly enantio- and diastereoselective HDA reaction of Brassard type diene 1b with aldehydes, to afford the corresponding 5-methyl-containing alpha,beta-unsaturated delta-lactone derivatives in moderate yields, high enantioselectivities (up to 99% ee) and excellent diastereoselectivities (up to 99:1 anti/syn). On the basis of the absolute configuration of 4a-4j disclosed by X-ray diffraction and CD analysis, a possible transition-state model for the enantio- and diastereoselective catalytic reaction has been proposed.
Lin
Lili
L
Key Laboratory of Green Chemistry and Technology (Sichuan University), Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
Fan
Qian
Q
Qin
Bo
B
Feng
Xiaoming
X
D007783:Lactones / Q000138:chemical synthesis*; D008958:Models, Molecular; D015394:Molecular Structure
D007783:Lactones