Prostaglandins and congeners. 21. Synthesis of some cyclohexyl analogs (11.alpha.-homoprostaglandins)

Synthesis and Biological Activity of a Novel 11a-Homo (Cyclohexyl) Prostaglandin

“…We were mindful at the outset of our studies of two previously published reports concerning the synthesis of 11a-homo PGF 2 α analogues 4 and 5 . , The authors' qualitative observations were that these ligands are less potent in the appropriate FP receptor-linked assay than is PGF 2 α . We felt that a better test for the viability of cyclohexyl FP receptor agonists would be to perform this modification on the a ligand known to be a more potent agonist at the FP receptor, namely cloprostenol ( 6 ) .…”

Creation of Highly Congested Quaternary Centers via Cu-catalyzed Conjugate Addition of Alkenyl Alanates to β-Substituted Cyclic Enones

“…In the 1970s, Weiss and co-workers exploited lithium ( E )-1-alkenylalanates for the synthesis of prostaglandines and congeners (Scheme ) . They showed that lithium alkenylalanates undergo conjugate addition to cyclopentenones in the absence of a metal catalyst at room temperature to give the addition products in poor to good yields.…”

“…Before investigating the Cu-catalyzed conjugate addition with alkenylalanates A7 and A8 (Table , entries 3–6) we were interested if alane 9 would also be able to undergo clean 1,4-addition (entries 1–2). Moreover, we evaluated the noncatalyzed conjugate addition of Alanate A8 applying conditions described by Weiss and co-workers (Entry 7) …”

A mild, large-scale synthesis of 1,3-cyclooctanedione: expanding access to difluorinated cyclooctyne for copper-free click chemistry

“…Many attempts to effect direct dehydrobromination on 2 with various bases and solvent systems were made (KOH in isopropanol, DBU in toluene or dichloromethane, 26 and LiBr/ Li 2 CO 3 in DMF 27 ). All such attempts, however, failed to generate significant quantity of enone 5.…”