Epoxides and trans-chlorohydrins of 3-methoxycyclopentene and their use in conformational studies in the cyclopentane system

The stereoisomeric oxides of 3-methoxycyclopentene ( 3 and 4 ) and the four trans-chlorohydrins of the same olefin ( 6 - 9 ) were prepared by methods resembling those used previously in the cyclohexane system. Structure proofs were more difficult than in the cyclohexanes, but served to illustrate some interesting chemistry. Product ratios in the cleavage of each of the epoxides with hydrogen chloride were used to deduce the probable conformations of the four transition states, by comparing the results with those from the cyclohexane system. An unexpected outcome of the work was the new convincing evidence obtained for the intervention of chloronium ions in the addition of "hypochlorous acid" to the olefin.