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

Abstract

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.

Epoxide ring-opening approach to the synthesis of diverse trisubstituted cyclopentanes

“…It was hypothesized earlier, that the direction of a nucleophilic attack towards oxirane carbon atoms of 3-substituted cyclopentane oxiranes is defined by the structure of the corresponding transition states. 24,25 In the case of 1 and 2, the mechanism for the epoxide ring-opening reactions has been proposed (Scheme 3). The geometry of transition states 11 and 12, related to the nucleophilic attack at C1 or C2 carbon atom, suggests a distorted twist conformation.…”

Synthesis of Chloroalkoxy eicosanoic and docosanoic acids from meadowfoam fatty acids by oxidation with aqueous sodium hypochlorite

“…Bleach is a complex mixture of sodium hypochlorite and various chlorine species, therefore, the acetic acid also reacts with sodium hypochlorite to produce hypochlorous acid. Excess acetic acid serves an additional role in the transition state of this reaction by forming protonated hypochlorous acid which can react with the carbon-carbon double bond to produce a chloronium ion as shown in Scheme 2 (20). The alcohol then attacks the chloronium ion to produce both positional isomers of the chloroalkoxy eicosanoic acid.…”