First total synthesis of 10α-hydroxy-4-muurolen-3-one and its C10-isomer

An efficient synthetic route to muurolane type sesquiterpenes starting from (R)-carvone,employing allylic diazene rearrange-ment and the ring closing methesis (RCM) reaction as key steps,is described.The first asymmetric total synthesis of (-)-10α-hydroxy-4-muurolen-3-one B and (-)-10β-hydroxy-4-muurolen-3-one C was accomplished.Through the total synthesis,the absolute configurations of the natural products A,B and C were established.     

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.     

The first facile total synthesis of natural （3R,4R,6S）-3, 4-epoxybisabola- 7 （ 14 ）, 10-dien-2-one

3,4-Epoxybisabola-7(14),10-dien-2-one,a natural sesquiterpoind,was first synthesized from(-)-carvone through 7 steps,in an overall yield of 35.9%.The key step was the allylation and then a substrate-directable epoxidation was committed successfully.     

Synthesis and Bioactivity of Isosteviol Derivatives： A Facile Method for Preparation of Ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic Acid

In this paper, two new compounds, ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic acid 4 and its ethyl ester 5 were synthesized in good yield with a facile method that has never been reported. The mechanism of this reaction was discussed and the mono-hydroxymethylation of carbonyl compound with two α-hydrogens via Tollens＇ reaction was firstly achieved. Compounds 2-5 were tested for activity of inhibition against glycosidases, among which 5 displays good inhibition of β-glucosidase and α-mannase, respectively.     

An enantioselective formal synthesis of （-）-thujopsene

Dihydromayurone （3）, a key intermediate to synthesize （-）-thujopsene （1）, was efficient enantiocontrolled synthesized from （＋）-dihydrocarvone through 9 steps in an overall yield of 19.3%. The key step was the Simmons-Smith reaction.     

A Rapid and Convenient Synthetic Route to Novel 1,5-Benzodiazepine Derivatives of 5-Methyl-3-phenyl-2-oxo-Δ4-1,3,4-oxadiazolines from p-Acetylphenylsydnone and Their Pharmacological Activity

A simple and high yielding method for the integration of 1,5-benzodiazepines integrated with 5-methyl- 2-oxo-3-phenyl-△^4-1,3,4-oxadiazolines in 75%-90% yield by microwave irradiation is devised. Microwave-accelerated reaction was compared with thermal method. All the compounds were characterized by physical, analytical and spectral （IR, 1^H NMR, MS） data. Title compounds were screened for preliminary pharmacological activities.     

Synthesis and Antibacterial Activity of 8-Substituted Phenyl-1-pyridin-3-yl-5H-bis[1, 2, 4]triazolo[3, 4-b； 4＇, 3＇-d][1, 3, 4] thiadiazines

To find new structural leading compounds for the research of the multidrug resistant of antibacterial agents, five novel 8-substituted phenyl-l-pyridin-3-yl-5H-bis[1, 2, 4] triazolo[3, 4-b;4‘,3‘-d] thiadiazines were prepared from the corresponding intermediates of 3-(5-substituted phenyl[1,3,4]oxadiazol-2-ylmethylsulfanyl)-5-pyridin-3-yl-[1,2,4]triazol-4-ylamines via intramolecular cyclization and the antibacterial activity in vitro against Gram-postive (G^ ) and Gramnegatiye (G) bacteria was primarily evaluated.     

First total synthesis of （±）-malaysianone A and （±）-tanariflavanones B

A concise approach for the frst total synthesis of two naturally occurring flavanoids,（）-malaysianone A（1）and（）-tanariflavanones B（2）,has been accomplished with total yields of 12.9%and 10.4%,respectively.The key steps were regioselective deprotection and regioselective synthesis of 5-formaldehyde-8-hydroxy-2-[40-methyl-30-penteneyl]-dihydro-1-benzopyran（8）.     

Synthesis and Crystal Structure of Ethyl 4-（2-Chloro-4-fluorophenyl）-6-hydroxy-3-oxo-1,3-dihydro-5-isobenzofurancarboxylate

The crystal structure of the title compound(C17H12ClFO5,Mr=350.72) was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/c,with a=7.693(1),b=15.767(1),c=12.986(1),β=97.23(1)°,V=1562.6(2)3,Z=4,Dc= 1.491 g/cm3,λ(MoKα)=0.71073,F(000)=720,μ(MoKα)=0.280 mm-1,R=0.0563 and wR=0.1674.A total of 3592 unique reflections were collected,of which 2462 with Ⅰ2σ(Ⅰ) were observed.Five-membered lactone rings and hydroxyl-substituted phenyl rings are approximately coplanar with their dihedral angle of 4.1°.The dihedral angle between two different phenyl rings is 71.3°.To our interest,intramolecular O(1)-H(1)···O(4) hydrogen bonds could be found in each molecule.Intramolecular hydrogen bonds and intermolecular van der Waals force contribute to the stability of the structure.     

Crystal Structure of Bis(3-hydroxy-2-pyridyl)disulfide

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＢｉｓ（３－ｈｙｄｒｏｘｙ－２－ｐｙｒｉｄｙｌ）ｄｉｓｕｌｆｉｄｅＣｈｅｎＸｕｅ－Ｔａｉ；ＫａｎｇＢｅｉ－Ｓｈｅｎｇ；ＸｕＹｏｎｇ－Ｊｉｎ；ＨｕＹｏｎｇ－Ｈａｎ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＳｔｒｕｃｔ...     

A rapid and efficient synthesis of indoloquinolinone and its analogues under microwave irradiation

A rapid and efficient method was established for the synthesis of indoloquinolinone and its analogues using acid-promoted cyclization in the present of PPA. All the reactions were completed in good yields in lOmin under microwave irradiation.     

Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro[2,3-d]pyrimidin-4（3H）-one

The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4（3H）-one （C16H18N2O3, Mr = 286.32） has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167（14）, b = 13.113（1）, c = 8.378（1） A, β = 98.992（2）^o, V = 1488.4（3） A^3, Z = 4, Dc = 1.278, F（000） = 608, μ = 0.089 mm^-1, MoKa radiation （2 = 0.71073）, R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar.     

Synthesis and Crystal Structure of 3a-Hydroxy-3-phenyl-1,2,3,3a,8a-pentahydrocyclopenta [α]inden-8-one

1 INTRODUCTION Many organic substances of interest contain vari-ous types of rings and it becomes important to ex-plore and develop new approaches to appropriatelyfunctionalize medium and large rings. Free radicalcyclization reaction is a new strategy to constructdifferent types of cyclic compounds including biolo-gically active natural products and pharmaceuti-cals[1～4], and nowadays it is one of the importantresearch fields of organic chemistry. Up to date, noreport on the radical cycl…     

Microwave assisted one-pot tandem three-component synthesis of2,4,5-triary1-2-4-dihydro-3H-1,2,4-triazol-3-one derivatives

This work described a one-pot tandem three-component synthesis of 2,4,5-triaryl-2,4-dihydro-3H- 1,2,4-triazol-3-ones using a simple reaction between phenylhydrazines, benzaldehydes and phenyl isocyanates under microwave irradiation and solvent-free conditions in good to excellent yields.     

Synthesis and Crystal Structure of N,N′-4-aminomethyl-pyromellitic diimide

1 INTRODUCTION N,N?-4-aminomethyl-pyromellitic diimide (4-pmpmdwas firstly obtained[1] in 1989 as one of the bypro-ducts by refluxing equimolar quantities of pyrome-llitic anhydride, n-hexylamine and 4-aminomethyl py-ridine in dry DMF to assemble electronic donor-spa-cer-acceptor systems, but its structure and coordina-tion chemistry did not receive attention at that time.For 4-pmpmd, the entity of two methylene groups(-CH2-) between the rigid pyromellitic diimide (PMDcore and two fre…     

Synthesis and antitumor activity of 9-methyl-10-hydroxycamptothecin

A novel camptothecin analogue, 9-methyl-10-hydroxycamptothecin （4）, was unexpectedly synthesized from 10-hydroxycamptothecin in two steps. The key step included an efficient Mannich-type reaction. The overall yield was 47.2%. An ether analogue of 4, 9-methyl-10-benzylaminomethoxycamptothecin （5）, was also prepared. These new camptothecin analogues were evaluated for in vitro cytotoxicity against four human cancer cell lines, and exhibited more potent antitumor activities than contrals camptothecin and topotecan against several cancer cells.     

The First Total Synthesis of 3-Oxo-11, 12, 13-trihydroxyeudesm-4-ene

The first total synthesis of 3-oxo-11, 12, 13-trihydroxyeudesm-4-ene, a highly oxygenated natural eudesmane, was described.     

Selective synthesis of the two main progesterone metabolites, 3α-hydroxy-5α-pregnanolone (allopregnanolone) and 3α-hydroxypregn-4-en-20-one,and an assessment of their effect on proliferation of hormone-dependent human breast cancer cells

Russian Chemical Bulletin - A directed synthesis of two progesterone metabolites, allopregnanolone and 3a-hydroxy-pregn-4-en-20-one, from Δ16-pregnanolone and progesterone, respectively, was...     

Synthesis and Crystal Structure of [2-Hydroxy- 5-（4-hydroxy-3-phenyliminomethylbenzyl）-benzylidene]-phenyl-amine

The title compound [2-hydroxy-5-（4-hydroxy-3-phenyliminomethyl-benzyl）-benzylidene]-phenyl-amine （C27H22N2O2, Mr = 406.47） was synthesized by 5,5′-methylene-bissalicylal- dehyde with aminobenezene, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 4.4026（6）, b = 1.501（13）, c = 0.95818（12） nm, β = 90.868（2）°, V= 4.2813（9） nm^3, Z= 8, Dc= 1.292 g/cm^3,μ = 0.010, F（000） = 1744, R = 0.0576 and wR = 0.1450 for 3766 observed reflections with I 〉 2σ（I）. X-ray analysis reveals that the molecule has a pair of intramolecular OH…N hydrogen bonds.