The firststereoselectivesynthesis of the naturally occurring conjugated diyne oplopandiol is reported. The pivotal functionalities are derived from CadiotsChodkiewicz cross‐coupling reaction, OhiraBestmann alkynation, asymmetric Noyori reduction, and cis‐olefination reaction
The influence of α-coordinating groups of aldehydes on <i>E</i>/<i>Z</i>-selectivity and the use of quaternary ammonium counter ions for enhanced <i>E</i>-selectivity in the Julia–Kocienski reaction
Modified reaction conditions for improved E-selectivity of olefins in the Julia–Kocienski reaction of aldehydes having α-coordinating substituents are demonstrated. The chelating groups in aldehydes are expected to stabilize the syn-transition state with metal ions, whereas the weakly coordinating quaternary ammonium ions are devoid of all possible chelating interactions to enhance E-selectivity. A