摘要:

Eight spirobenzylisoquinolines and four phthalideisoquinolines have been synthesized through 1,9-dehydrophthalideisoquinoline intermediates. The latter are reduced and rearranged in one step to spirobenzylisoquinolines of the corydaine–sibiricine type. The phthalideisoquinoline alkaloid hydrastine has been converted byinvitromethods to a spirobenzylisoquinoline in two steps.

ISSN:0008-4042    

DOI:10.1139/v79-252

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The13Cmr spectra of several cholestanes including 13A-homo-B-nor derivatives, 11A-homo derivatives, and 8B-nor examples have been examined. In addition the13C data for a few of the corresponding androstanes and 16 precursors in the cholestane series are reported. Examples in both the 5α- and 5β-cholestane families were included. These results represent the first systematic examination of the13C spectra ofA-homo-B-nor steroids and should be useful for the characterization of other members in each series. These data also permit some tentative conclusions regarding the favored conformation for the seven-membered ring in theA-homo derivatives.

ISSN:0008-4042    

DOI:10.1139/v79-253

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Several ring-expansion reactions (diazomethane, diazoacetic ester, Tiffeneau–Demjanov, Baeyer–Villiger, and Schmidt) of 3-keto steroids have been reexamined to determine the true migration ratios for C-2 and C-4 in these unsymmetrical cyclohexanones. Migration ratios were measured to ±3% accuracy by integration of baseline-separated signals in the proton-decoupled13Cmr spectra of total reaction products. This underexploited method provides for the first time a way to get accurate migration ratios without loss of components during separation and without interference from excess starting material under conditions minimizing side reactions. In contrast to numerous literature reports, all but one of the 16 reactions studied were found to give nearly the same amount of both possibleA-homo products. (The single exception was the only reaction in which theA-homo product reacts markedly faster than the starting material.) This simple, consistent ∼1:1 pattern is that expected if migration is governed mainly by the electronic effect of the α- and α′-carbon atoms and not by any conformational or near-by-to-remote substituent effect.

ISSN:0008-4042    

DOI:10.1139/v79-254

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The strategy outlined previously has been developed to provide, in principle, routes to any known spirobenzylisoquinoline alkaloid. The generality has been demonstrated by the synthesis of the racemic forms of corydaine, yenhusomidine, corpaine, sibiricine, and raddeanone.

ISSN:0008-4042    

DOI:10.1139/v79-255

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Ethyl-3-(1-ethoxycarbonyl-2,6-dimethylcyclohex-2-enyl)propionate5was stereoselectively synthesized. The diester5was spiroannulated by the acyloin condensation to give the bis(tri-methylsiloxy) ether11. The ether11was hydrolyzed to provide the acyloins6and12. The acyloins6and12were elaborated into (±)-hinesol1, (±)-agarospirol2, (±)-β-vetivone3, and (±)-α-vetispirene4.

ISSN:0008-4042    

DOI:10.1139/v79-256

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The products arising from the incubations of C-6α and C-6β chloro-, fluoro-, and methyl-substituted Δ4-3-keto steroids with the C-6β hydroxylating fungusRhizopusarrhizusATCC 11145 have been identified, and their formation rationalised in terms of Δ3,5enolic intermediates. The incubations of C-6 chloro and methyl Δ3,5enol acetates withR.arrhizus, and the oxidations bym-chloroperoxybenzoic acid of the corresponding enol ethyl ethers have also been described. The relevance of the results so obtained to the mechanism of C-6β hydroxylation of Δ4-3-keto steroids byR.arrhizusis discussed.

ISSN:0008-4042    

DOI:10.1139/v79-257

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The biosynthesis of berberine and hydrastine (inHydrastis canadensis), corydaline and protopine (inCorydalis solida), and ochotensimine and protopine (inC.ochotensis), has been investigated by the administration of [3-14C]-3′,4′-dihydroxyphenylalanine ([3-14C]DOPA). In all cases, incorporation of label was predominantly into the isoquinoline portion of the alkaloid. The role of DOPA in the early stages of isoquinoline alkaloid biosynthesis in these plants is discussed in the light of this and other relevant data. In addition, the later stages of corydaline biosynthesis have been studied by the administration of [9-methoxy-14C]palmatine and -tetrahydropalmatine toC.solida, and the origin of the exocyclic carbons of ochotensimine further verified by feeding [methyl-14C,3H]methionine toC.ochotensis.

ISSN:0008-4042    

DOI:10.1139/v79-258

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Diastereomeric phthalideisoquinolines8and9have been synthesized by a route involving an amine-induced bromohomophthalic anhydride – phthalide-α-carboxamide rearrangement,3 + 4 → 6, as the key step. This rearrangement has been applied to the synthesis of the methoxylated phthalide-α-carboxamide18which has been converted into the dehydrophthalide19thereby achieving a formal synthesis of the phthalideisoquinoline alkaloids cordrastine I (1a) and cordrastine II (1b). The key intermediate in this sequence, 3,4-dimethoxyhomophthalic acid (15), has been efficiently prepared in two steps via directed lithiation of 2,3-dimethoxy-N,N-diethylbenzamide (13).

ISSN:0008-4042    

DOI:10.1139/v79-259

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The biosynthesis of decodine (7) and decinine (9), Lythraceae alkaloids containing atrans-fused quinolizidine nucleus, was studied in intact plants ofDecodonverticillatus(L.) Ell. Nonrandom incorporation of radioactivity from14C-labelled samples of lysine, cadaverine, and Δ1-piperideine was demonstrated by partial degradation. Pelletierine did not serve as a precursor of the alkaloids. It was also shown, by means of3H,14C-labelled tracers, that the alkaloids are derived fromL-lysine whereas pipecolic acid, which is present in the plant, is derived fromD-lysine.

ISSN:0008-4042    

DOI:10.1139/v79-260

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Label from [1-14C]-, [2-14C]-, [3-14C]-, and [1,3-14C2]phenylalanine is incorporated non-randomly into the Lythraceae alkaloids, decodine and decinine, inDecodonverticillatus. The incorporation pattern, determined by chemical degradation of the alkaloids, demonstrates incorporation of two intact C6—C3units.

ISSN:0008-4042    

DOI:10.1139/v79-261

出版商:NRC Research Press    

年代:1979

数据来源: NRC