oxidative cyclization of 2-(3-pentenyl)phenol catalyzed by [(η3-pinene)PdOAc]2 gives optically active (+)-2-vinylchroman (25% e.e.), while (−)-2-(1-hydroxyethyl)chroman (56% e.e.) is formed as a single diastereomer upon treatment with t-BuOOH in the presence of Ti(OiPr)4 and l-(+)-diethyl tartrate. 2-(2-Butenyl)phenol also undergoes the Ti-promoted asymmetric cyclization to give (2S,1′R)-(−)-2-(1-hydroxyethyl)-2
This article describes an efficient method for the preparation of chiral chroman derivatives by the Pd(II)-catalyzed asymmetricWacker-typecyclization using a chelation-induced axially chiral tetraoxazoline ligand. Under the optimized conditions, up to 80% yield and up to 92% ee were obtained. This is the first example to utilize o-trisubstituted 3-butenylphenols as substrates in such transformation