... Tetrahedron. Volume 57, Issue 30, 23 July 2001, Pages 6375–6382. ... of 8:1, while work-up, after the reaction was allowed to stand at room temperature for 4 h following disappearance of starting material, afforded a mixture (S,α-S)-9a and (S,α-R)-10a with up to 94% de (30:1 ratio ...