An efficient enantio- and stereocontrolled total synthesis of (+)-boronolide from valeraldehyde is described. The key steps include a Sharpless asymmetricdihydroxylation, a chelation controlled Grignard reaction followed by Sharpless asymmetric epoxidation and a ring closing metathesis.
A seteroselective total synthesis of (+)-boronolide is described. The key steps are Sharpless asymmetric dihydroxylation, Shibasaki's asymmetric Henry reaction, asymmetric allylation and ring closing metathesis. (c) 2005 Elsevier Ltd. All rights reserved.