I've been reading about diastereoselective epoxidation of acyclic alkenes with VO(acac)2. This is taken from Carey, Sundberg Advanced Organic Chemistry Part B: The OH and epoxide are syn. Then, while reading Smith's Organic Synthesis I've found this (the ratio of products is 5.6:1 in favor of the anti): which is in contrary with the results from Carey, Sundberg. In an Evans lecture the syn stereoselectivity is explained while in this lecture the anti selectivity is explained. Apparently different sources give opposite selectivities. What is the true explanation here? Is the syn or anti selectivity predominant?