Olefinic cyclizations. XI. Allylic cation promoted olefinic cyclizations. The stereospecific formation of a tricyclic system and the total synthesis of dl-fichtelite

1, 4-Addition of Terminal Alkynes to Conjugated Enones in Water Using Green Catalyst Bis[(l)prolinato-N,O]Zn—An Environmentally Benign Protocol

“…Moreover only one method has been explored, which employs zinc catalyst for the alkynylation of the enones [22]. This is very unfortunate for the researchers as c, d-acetylenic ketones are valuable synthetic intermediates, since they are easily converted to a variety of important structural classes such as 1,4-diketones [23], 1,5-dienes [24], furans [25], pyrroles [26], synthesis of prostaglandin analogs [27,28]. In case of benzalacetophenone as a reactant synthesis of jasmone can also be achieved [29,30].…”

Stereoselective formation of 1,2-diiodoalkenes and their application in the stereoselective synthesis of highly functionalised alkenes via Suzuki and Stille coupling reactions

“…4-Benzyloxybut-1-yne was prepared according to the literature. 12 The solvents used were either purchased as anhydrous or distilled before use over either benzophenone-sodium (THF) or calcium hydride (all remaining solvents) under an atmosphere of argon.…”

Alkene–alkyne metathesis and 1,4-cis-hydrogenation as a route to tetrasubstituted (Z)-olefins

“…The readily available acetate of 5-benzyloxypent-2-yn-1-ol 3, 18 upon metathesis with ethylene in CH 2 Cl 2 under the Mori conditions, 13,14 afforded target conjugated diene 4 with a maximum conversion of 43%. † Attempts to improve the process were unsuccessful.…”