88046-48-4Relevant academic research and scientific papers
Asymmetric Synthesis of Carbocyclic Propellanes
Schneider, Lisa M.,Schmiedel, Volker M.,Pecchioli, Tommaso,Lentz, Dieter,Merten, Christian,Christmann, Mathias
supporting information, p. 2310 - 2313 (2017/05/12)
A modular synthesis of functionalized carbocyclic propellanes was developed. Formation of the first of two quaternary bridgehead centers has been achieved by desymmetrization of prostereogenic ketones by either Hajos-Parrish-Eder-Sauer-Wiechert-type processes or Werner’s catalytic asymmetric Wittig reaction. The obtained bicyclic enones were subjected to conjugate additions upon which the remaining ring was formed by olefin metathesis. All bridges are amenable to further derivatization, which renders those compounds useful as central units in fragment-based drug discovery or as ligand scaffolds.
New Synthetic Approaches to Fused-ring Carbocycles based on Intramolecular Photocycloadditions of 1,3-Dione Enol Esters
Begley, Michael J.,Mellor, Michael,Pattenden, Gerald
, p. 1905 - 1912 (2007/10/02)
Irradiation of 3-acetoxy-2-pent-4-enylcyclohex-2-enone (12) leads to the tricyclic adduct (18), in high yield (>95percent), which on hydrolytic cleavage in ethanolic potassium hydroxide gives rise to bicycloundecane-2,6-dione (20).In contrast, irradiation of the isomeric enol acetate, 3-acetoxy-4-pent-4-enylcyclohex-2-enone (17) led to the two photoadducts (25) and (26) resulting from intramolecular photocycloaddition, and to the trione (24) produced via photo-Fries rearrangement of (17); the formation of (25) and (26) followed from the structures (29) and (27) produced after saponification-retroaldolisation of mixtures containing (25) and (26).Irradiation of the 6-phenyl substituted enol ester (16) gave rise to only the photo-Fries rearrangement product (24).Irradiation of 1-acetoxy-2-pent-4-enylcyclopentene (39) led (93percent) to a 2:3 mixture of the photoadducts (41) and (42) whose structures followed from X-ray measurements.The corresponding cyclohexene (45), instead produced the product (46) of photo-Fries rearrangement on irradiation.Hydrolytic cleavage of (41) in KOH-EtOH leads to the bicyclodecanone (47), whereas similar treatment of (42) instead gave directly the aldol (49) by way of the transient retro-aldol intermediate (48).
