Constituents of Solidago Species. Part V. Non-acidic Diterpenoids from Solidago gigantea var. serotina

1973 ◽  
Vol 51 (9) ◽  
pp. 1346-1358 ◽  
Author(s):  
M. S. Henderson ◽  
R. McCrindle ◽  
D. McMaster
Keyword(s):  
Total Synthesis ◽  
Related Compound ◽  
Chromium Trioxide ◽  
Allylic Oxidation ◽  
Spectroscopic Evidence ◽  
Solidago Gigantea ◽  
Pyridine Complex ◽  
Related Compounds ◽  
Leonotis Leonurus

Eight new furan-containing diterpenoids from Solidago gigantea Ait. var. serotina (Kuntze) Cronqu., are formulated as 1c–g, 2, 3a, and 4a on the basis of chemical and spectroscopic evidence and by correlation with solidagoic acid A of previously defined constitution and stereochemistry. The structure (5a) of a ninth related compound is tentatively assigned. The allylic oxidation of some of these new diterpenoids and related compounds with the chromium trioxide – pyridine complex is reported. In the course of this investigation of formal total synthesis of compound Y from Leonotis leonurus was achieved.

Correction. Allylic Oxidation of Olefins with Chromium Trioxide-Pyridine Complex

1971 ◽  
Vol 36 (23) ◽  
pp. 3657-3657
Author(s):  
William Dauben ◽  
Milton Lorber ◽  
Dwight Fullerton
Keyword(s):  
Chromium Trioxide ◽  
Allylic Oxidation ◽  
Pyridine Complex ◽  
Oxidation Of Olefins

Allylic oxidation of olefins with chromium trioxide pyridine complex

1969 ◽  
Vol 34 (11) ◽  
pp. 3587-3592 ◽  
Author(s):  
William G. Dauben ◽  
Milton E. Lorber ◽  
Dwight S. Fullerton
Keyword(s):  
Chromium Trioxide ◽  
Allylic Oxidation ◽  
Pyridine Complex ◽  
Oxidation Of Olefins

Total Synthesis ofdl-Ascofuranone and Related Compounds

1995 ◽  
Vol 68 (9) ◽  
pp. 2727-2734 ◽  
Author(s):  
Hiroyuki Saimoto ◽  
Shin-ichiro Ohrai ◽  
Hitoshi Sashiwa ◽  
Yoshihiro Shigemasa ◽  
Tamejiro Hiyama
Keyword(s):  
Total Synthesis ◽  
Related Compounds

Studies Directed Towards the Total Synthesis of Anticapsin and Related Compounds. IV. Competitive Reaction of Amino and Carboxy Substituents in the Halohydrination of 2-Aminobicyclo[2.2.2]oct-5-ene-2-carboxylic Acid Derivatives

1994 ◽  
Vol 47 (12) ◽  
pp. 2221 ◽  
Author(s):  
MJ Crossley ◽  
SR Davies ◽  
TW Hambley
Keyword(s):  
Total Synthesis ◽  
The Other ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
Competitive Reaction ◽  
Trimethylsilyl Group ◽  
X Ray ◽  
Tricyclic Compounds ◽  
Tricyclic Compound ◽  
Related Compounds

Bromohydrination of benzyl (1RS,2SR,4SR)-2-benzyloxycarbonylamino-1-trimethylsilyloxy-bicyclo[2.2.2]oct-5-ene-2-carboxylate (6a) and the (1RS,2RS,4SR)- diastereomer (6b) with N- bromoacetamide in aqueous dioxan has been investigated. These reactions are highly regio-and stereo-selective and give the corresponding bromohydrins (9a) and (9b), but in moderate to low yield. These bromohydrins have the necessary stereochemistry for conversion into anticapsin. The other products from the reaction are tricyclic compounds formed by capture of the anti- bromonium cation intermediates or resultant bromohydrins by interaction with the proximal protected carboxy and amino groups within the molecules. Thus the carbolactone (11) is formed from the endo -adduct (6a), and the carbonimidic acid derivative (12) and the cyclic urethane (13) are formed from the exo-adduct (6b). Cleavage of the trimethylsilyl group from the tricyclic compound (12) gives benzyl (1RS,2RS,3RS,7RS,8RS)-5-benzyloxy-2-bromo-8-hydroxy-4-oxa-6-azatricyclo[5.3.1.03,8]undec-5-ene-7-carboxylate(14), the structure of which was determined by X-ray diffraction methods and refined to a residual of 0.035 for 1549 independent observed reflections. The crystals of (14) are monoclinic, P21/c, a 12.954(3), b 6.197(3), c 26.784(7) Ǻ, β 95.33(2)°, Z 4. Reactions attempting to generate iodohydrins from the alkenes (6) were also highly regioselective and gave detrimethylsilylated iodo analogues of (11) and (13).

Total synthesis of novel conduritol related compounds capable of modulating insulin release.

1994 ◽  
Vol 4 (19) ◽  
pp. 2307-2312 ◽  
Author(s):  
D.C. Billington ◽  
F. Perron-Sierra ◽  
I. Picard ◽  
S. Beaubras ◽  
J. Duhault ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Insulin Release ◽  
Related Compounds

A Concise Total Synthesis of (±)-Mesembrine

Synlett ◽  
2018 ◽  
Vol 29 (09) ◽  
pp. 1203-1206 ◽  
Author(s):  
Hyoungsu Kim ◽  
Hosam Choi ◽  
Kiyoun Lee
Keyword(s):  
Total Synthesis ◽  
Claisen Rearrangement ◽  
Addition Reaction ◽  
Conjugate Addition ◽  
Allylic Oxidation ◽  
Quaternary Stereocenter

A concise total synthesis of (±)-mesembrine has been successfully accomplished in seven steps and 24% overall yield from commercially available 3-ethoxy-2-cyclohexen-1-one. Central to the assembly of the skeleton of mesembrine are a Johnson–Claisen rearrangement for the formation of the benzylic quaternary stereocenter and direct allylic oxidation to generate the substrate for the amidation/transannular aza-conjugate addition reaction.

Allylic oxidation with 3,5-dimethylpyrazole. Chromium trioxide complex steroidal .DELTA.5-7-ketones

1978 ◽  
Vol 43 (10) ◽  
pp. 2057-2059 ◽  
Author(s):  
William G. Salmond ◽  
Mary A. Barta ◽  
Jeffrey L. Havens
Keyword(s):  
Chromium Trioxide ◽  
Allylic Oxidation
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