Die absolute konfiguration des (+)-corynolins

Chemical Study on Alkaloids from Corydalis bulleyana

“…The fragmentation patterns in the mass spectra of alkaloid 5 and (+)consperine (2) (4) were the same, however, with different abundances of some of the peaks. This was quite similar to the difference between (+)acetylisocorynoline (6) and (+)acetylcorynoline(3) as well as between (+)isocorynoline (10) and (+)corynoline (8).…”

“…Alkaloid 12 had the same UV absorption as that of (+)12-hydroxycorynoline (19). A molecular ion at rn/c 411.1262, consistent with molecular formula of C22H2107N, was observed and characteristic chemical shifts of 14…”

Efficient Synthesis of (−)‐Corynoline by Enantioselective Palladium‐Catalyzed α‐Arylation with Sterically Hindered Substrates

“…DeN-corynoline [7] is ap otent anti-inflammatory and/or immunosuppressive agent that is more active than corynoline in inhibiting the adhesion of human polymorphonuclear leukocytes and eosinophils to human umbilical vein cultured endothelial cells.T he reported synthesis of DeN-corynoline required four steps from corynoline by degradation. Using the asymmetric a-arylation method, we successfully synthesized (À)-DeN-corynoline (5)f rom indanone 14 in 40 %o verall yield through only three steps.T he synthesis was accomplished through an arylation to form 16,f ollowed by aB üchner-Curtius-Schlotterbeck reaction to yield 20,a nd af inal LAH reduction.…”

“…The search for asymmetric catalytic methods for the efficient construction of all-carbon quaternary centers continues to be amajor interest in organic synthesis.Inparticular, asymmetric catalytic methods applicable to the synthesis of chiral natural products and therapeutic agents containing all-carbon quaternary centers remain in high demand. [1,2] Chiral 2-alkyl-2aryl-1,2,3,4-tetrahydronaphthalene and quinoline motifs are found in many biologically important natural products and drugs,s uch as the antidepressant (S)-nafenodone (1), [3] the Sceletium alkaloids (+ +)-sceletium A-4 (2) [4] and (+ +)-tortuosamine (3), [5] as well as the acetylcholinesterase inhibitors (+ +)-corynoline (ent-4), [6] (+ +)-DeN-corynoline (ent-5), [7] and corynoloxine (6; Figure 1). [8] Although there has been agreat deal of synthetic effort, efficient asymmetric syntheses,i n particular those based on asymmetric catalytic methods,a re still lacking.…”

X-ray Structure Analysis of (dl)-DeN-Corynoline, Derived from Hexahydorobenzo[c]phenanthridine Type Alkaloid Corynoline

“…3 According to Emde degradation under a reductive condition, 4 (dl)-1 was derived from (dl)-2 by the same procedure as previously reported. 5 Single crystals of (dl)-1 were obtained from methanol/acetone at room temperature as transparent plates. Crystallographic data and the analysis method are shown in Table 1.…”