Total Synthesis of Anisodine

Aim To design a practical synthetic route of anisodine. Methods Starting from3α-hydroxy-6β-acetyltropine, anisodine was synthesized in 11 steps. Result Anisodine wasobtainded with an overall yield of 2.6 % . Conclusion Total synthetic route of anisodine wasachieved which may afford a possible route for commercial preparation of anisodine.

First total synthesis of (±)-abyssinoflavanone V

The total synthesis of （±）-abyssinoflavanone V was first achieved through C-prenylation, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap 4-hydroxybenzaldehyde and 2,4,6- trihydroxyacetophenone, with total yield 24%. All structures of new compounds were confirmed by IR, 1^H NMR and MS.

First total synthesis of two nematicidal prenylated flavanones

The total synthesis of （＋）-8-（3-methylbut-2-enyl）-2-phenyl-2,3-dihydrochromen-4-one and （±）-2-（4-hydroxyphenyl）-8-（3- methylbut-2-enyl）-2,3-dihydrochromen-4-one was first achieved through C-prenylation, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxyace- tophenone, with total yield of 20 and 16.3%. All structures of new compounds were confirmed by IR, 1H NMR and MS. 2009 Jin Hui Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Total synthesis of bis-(2,3-dibromo-4,5-dihydroxyphenyl)-methane as potent PTP1B inhibitor

Protein tyrosine phosphatase 1B （PTP1B） plays an important role as a negative regulator and has been proved to be an effective target for the treatment of type 2 diabetes mellitus. Bis-（2,3-dibromo-4,5-dihydroxyphenyl）-methane 7 was first reported as a natural bromophenol with significant inhibition against PTP1B which was isolated from red algae Rhodomela conrervoides. Intrigued by its astonishing activity （IC50 = 2.4 μmol/L）, compound 7 was synthesized with the overall yield of 24% and evaluated for its PTPIB inhibitory activity compared with natural compound.

Total synthesis and anticancer activity studies of the stereoisomers of asperphenamate and patriscabratine

All stereoisomers of asperphenamate 1a and patriscabratine 2a were achieved with a high yield,and total synthesis of 2a is firstly described here.The absolute configuration of patriscabratine was determined as(S,S).The compounds 1a-d and 2a-d have been tested by MTT assay in T47D,MDA-MB231,HL60,Hela and SGC-7901 cell lines in vitro.Among them,the(R,S) stereoisomer shows the strongest anticancer effects,while the(S,R) shows the weakest one.

A new isochroman-4-one derivative from the peel of Musa sapientum L.and its total synthesis

A new isochroman-4-one, 7,8-dihydroxy-3-methylisochroman-4-one was isolated from water soluble fraction of Musa sapientum L. Its structure was determined by spectroscopic evidences and its total synthesis has also been reported. The compound showed potent antihypertensive activity.

First total synthesis of (±)-puyanin and (±)-4'-O-methylbonannione

A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids,（±）-puyanin 1 and（±）-4＇-O- methylbonannione 2 has been obtained with total yield 27%and 21%,respectively.The key steps were regioselective cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2,4,6-trihydroxyacetophenone.

TOTAL SYNTHESIS OF SQUAMOSAMIDE

The first synthesis of squarnosamide,a new compound isolated from Annona squamosa, was achieved in seven steps.The over all yield was 14%.The compound was identified by^1 H,^(13)C NMR and MS.

Total Synthesis of (±) Kadsurenin M

Kadsurenin M (7s, 8s- 3, 4, 3'- trimethoxy- 7'- o\o- nor-8', 9'-7. O, 4' - 8, 5'-neolingan)(1), a benzofuranoid neolignan isolated tyom the aerial part of Piper Kadsura (Choisy) Ohwi,was synthesized in 6 steps from vanillin via a key intermediate 3,4- dimethoxycinnamyl (2'-methoxy- 4'- formyl)phenyl ether (7). The overall yield is 15%.

Total Synthesis of (±)-Calanolide A and Its Anti-HIV Activity

Anti-HIV agent (±)-calanolide A has been synthesized by a four-step approach startingfrom phloroglucinol, including the Pechmann reaction, Friedel-Crafts acylation, cyclization,chromenylation and Luche reduction.

Total synthesis and determination of the absolute configuration of a natural analgesic: crotonine

We report the first total synthesis of four possible absolute configurations and four other regional isomers of a naturally occurring alkaloid crotonine,which was isolated from Croton tiglium L.(Euphoriaceae)without elucidation of its absolute configuration.The concise five-step route with a chirally poor and regioselective strategy starting from monosaccharides was established,and the absolute structure of the natural crotonine was determined by comparison of the NMR spectra and optical rotations of the synthetic products.

Total Synthesis of the Natural Product-Pinosylvin and its Analog

We synthesised a natural product (10), isolated from G. parvifolium, and its analog. The synthetic product was characterized by elemental analysis and H-1-NMR in comparision with the corresponding natural product.

STEREOSELECTIVE TOTAL SYNTHESIS OF(±)-4α(H)-EUDESMANE

The first stereoselective total synthesis of the biomarker(±)-4α(H)-eudesmane 1,starting from (-)-carvone in five steps,has been described.

First Total Synthesis of 12-Hydroxy-13-methylpodocarpa-9, 11, 13-trien-3-one

A ftrst facile total synthesis of 12-hydroxy- 13-methylpodocarpa-9, 11, 13-trien-3-one 9 was accomplished via a strategy of AC→ABC. In the synthetic process, compound 5 was synthesized through Reimer-Teimann reaction, followed by methylation, reduction, dehydration, addition to ethylene epoxide and chlorination. The target compound 9 was finally obtained through the condensation of Grignard reagent of compound 5 with 6, followed by intramolecular cyclization, reduction and demethylation.

Total synthesis of glypetelotine

A total synthesis of glypetelotine, the first sulphur-containing indole alkaloid from the leaf extracts of Glycosmis petelotii collected in the north of Vietnam, was described from indole through 6 steps. The structure of the glypetelotine was confirmed by IR, 1H NMR, 13C NMR and MS analysis. The spectral data of synthetic compound was identical with those of natural compound.

The Total Synthesis of 14-Deoxycrassin and Pseudoplexaurol: A Convergent Synthesis of Cyclization Precursor

The synthesis of epoxy aldehyde 4, a cyclization precursor for the total synthesis of 14-deoxycrassin and pseudoplexaurol, starting from geraniol in a convergent and stereoselective manner, is described.

TOTAL SYNTHESIS OF NEOCLAUSENAMIDE AND ITS EPIMER

The natural product, neoclausenamide was synthesized through the 'biomimetic' route and the stereoselective reduction of the ketone group wherein were described.

Total Synthesis of Bilobetin and Isoginkgetin

Total synthesis of bilobetin and isoginkgetin has been achieved by Pd(PPh3)(4) catalytic coupling of 8-flavone-boronic acids with iodoflavones.

Total Synthesis of Three New Dihydrostilbenes from Bulbophllum odoratissimum

A total synthesis of three new dihydrostilbenes, 1, 2 and 3, which were isolated from Bulbophyllum odoratissimum Lindl. with significant cytotoxicity toward human cancer cell lines, was developed via Homer reaction etc. The natural products 1, 2 and 3 were obtained in 5.8%, 6.6% and 5.9%, respectively.

First total synthesis of (±)-trolline

Trolline, a new bioactive alkaloid was isolated in 2004. We reported herein the first total synthesis of (±)-trolline, in two steps and 18.0% overall yield.