Conjugate addition to chiral γ-heterosubstituted δ-lactones as pivotal synthons from L-glutamic acid. Synthesis of an optically active lignan lactone; (−)-hinokinin
Asymmetric induction in conjugateaddition of new chiral γheterosubstituted-α,β-unsaturated α-lactones from L-glutamic acid was accomplished in high diastereoselectivity with the formation of trans(R,S)-adducts and was disclosed to serve as a versatile procedure for the asymmetric synthesis of antileukemic lignanlactones.