BF3·OEt2-promoted diastereoselective diacetoxylation of alkenes by PhI(OAc)2.

Wenhe Zhong, Jun Yang, Xiangbao Meng, Zhongjun Li

Index: J. Org. Chem. 76(24) , 9997-10004, (2011)

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Abstract

Selective syn and anti diacetoxylations of alkenes have been achieved using a PhI(OAc)(2)/BF(3)·OEt(2) system in the presence and absence of water, respectively. A broad range of substrates including electron-deficient alkenes (such as α,β-unsaturated esters) could be elaborated efficiently at room temperature with this methodology, furnishing the desired products in good to excellent yields and diastereoselectivity. In particular, a multigram-scale diastereoselective diacetoxylation of methyl cinnamate (5.00 g) was also accomplished in a few hours, maintaining the same efficiency as small-scale reaction. This novel methodology provides an alternative approach for the preparation of various 1,2-diols.