Synthesis of (24R)-3β,5,14α-trihydroxy-5α-stigmast-7-en-6-one 3-benzoate

An ecdysteroid analog has been synthesized from -sitosterol.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus', 220141, Belarus', Minsk, ul. Akad. Kuprevich, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 488–491, July–August, 1999.     

Synthesis of 3β,6α-dihydroxy-5α-cholan-23-one

Evidence for the presence of 3β,6α-dihydroxy-5α-chol-9(11)-en-23-one in the aglycone mixture from the starfish Marthasterias glacialis is provided by the synthesis of 3β,6α-dihydroxy-5α-cholan-23-one (19) and its identification in the hydrogenated aglycone mixture. The side-chain is constructed from the 23,24-dinorcholanol (13) by reaction of the 22-tosylate (16) with the acetylide anion, followed by hydration of the resulting 23-yne (17).     

Synthesis of (24R)-3β-hydroxystigmast-5-en-7-one

The natural compound (24R)-3-hydroxystigmast-5-en-7-one has been synthesized from -sitosterol.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus', 220141, Belarus', Minsk. Ul. Akad. Kuprevicha, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 484–487, July–August, 1999.     

First Total Synthesis of 3α,4α-Oxidoagarofuran and (-)-3β,4α-Dihydroxy-β-dihydroagarofuran

The first stereoselective total synthesis of (–)-3β, 4α-dihydroxy-β-dihydroagarofuran (1) and 3α, 4α-oxidoagarofuran (2) has been described. The key step is the epoxidation of α-agarofuran (6) with dimethyldioxirane.     

Synthesis of (22R,23R,24S)-24-Methyl-5α-cholestane-3β,6α,22,23-tetraol, a Biosynthetic Precursor of Brassinolide

A biosynthetic precursor of brassinolide, (22R,23R,24S)-24-methyl-3-cholestane-3,6,22,23-tetraol was synthesized from ^{2 3}-22-keto steroid which was obtained from the corresponding 20-carbonitrile oxide. The side chain was built up by a series of successive transformations: hydride reduction of the initial enone, epoxidation of the allyl-like alcohol, and copper(I) cyanide-catalyzed opening of the 23,24-epoxy ring. The cyclic fragment was completed by opening of the cyclopropane ring with subsequent hydroboration and oxidation of the ⁵-bond.     

Synthesis of 25R-3β-chlorine-furosta-5,20(22)-dien-26-ol

A new 3β-chlorine steroids derivative of 25R-3β-chlorine-furosta-5,20(22)-dien-26-ol (1) was synthesized in which 3-methoxydiosgenin (3) of both rings, E and F, were opened under the influence of ammonium chloride in acetic anhydride. The structure of 1 was determined by ¹H, ¹³C NMR, IR, MS spectra, and X-ray diffraction. The mechanism for forming the new compound 1 has been briefly explored.     

Synthesis and Characterization of (25R)-2α,3α-Epoxy-5α-Spirostan-12,23-Dione

The synthesis and spectroscopic characterisation of (25R)-5oc-spirostan-12,23-dione is described     

Synthesis of 5α-Iodo-6-one Steroids

Abstract: The synthesis of 5-iodo-5α-cholestan-6-one (6), its 3β-acetoxy-(7) and 3β-chloro-(8) analogues, 3β-acetoxy-5-iodo-5α-stigmastan-6-one (9) and its 3β-chloro-(10) analogue by the reacion of silver chromate-iodine and pyridine with the corresponding steroidal olefins (1-5) is described. The structures of these products have been established on the basis of their elemental, analytical and spectral data.     

Novel Synthesis of 2β,3β,20β-Triacetoxy-5 -pregnan-6-one

Pregnenolone (2) is used in a novel synthesis of 2,3,20-triacetoxy-6-ketosteroid (6), a key intermediate in the preparation of 20-hydroxyecdysone (1)     

Synthesis of (22S,23S,24S)-3β,14α,22,23-Tetrahydroxy-5α-stigmast-7-en-6-one, a New Ecdysteroid Analog

A tetrahydroxyketone that is a structural analog of ecdysteroids is synthesized from stigmasterol     

Synthesis of 6-chloronicotinates of steroidal 3β,5α,6β-triols and 3β,5-dihydroxy-6-ketones

New esters of 3β,5α,6β-trihydroxysteroids and 3β,5-dihydroxy-6-ketosteroids containing 6-chloropyridine groups characteristic of the alkaloid epibatidine were synthesized by acylation with 6-chloronicotinoylchloride. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 175-179, March-April, 2009.     

A Total Synthesis of (±)-α-Chamigrene-3-one

Thephotocycloadditionofmethyl2,4-dioxopentanoate1toalkenesorconjugatedolefins2regioselectivelygavethecycloadduct3(Schemel).ThisreactioncouldconvenientlybeusedtoconstructthebasicframeworkofvariousnatUraIlyoccutringchamigran-tyPespirosesquiterPenes,suchasa-chamigrene",6-chamigrene:=,andaseriesofrelatedhaIogenatedderivativesd.The(i)-Q-Chamigrene-3-onewasanewmemberofthisfamilyandwasrecentlyisolatedfromMarchantiapolymorPha".whichpossessedthestrUctUreofasyntheticintermediate,1-methoxycarbonyl-5,…     

Asymmetric Synthesis of (-)-(2R,3R,6S)-Irnigaine

Introduction　　Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan…     

A Facile Synthesis of 6β-Hydroxy-7α(H)-eudesma-4-en-3-one

Sesquiterpenesconstituteagroupofnaturalcompoundswhichexhibitconsiderablebiologicalactivities,suchasantiinflamatoryicytyotoxic'andcytotoxic',seedgendnation'andmolluscacidalactivities4.InrecentyearsanumberofC-6oxyfunctionalizedeudesmanesand6-dihydroagarofurans,suchascomPounds3-6',havebeenisolatedfromnaturesources.HoweverthereportSonthesynthesisofthisparticularkindofcompoundsarefewandthereportedsynthesesaregenerallybysyntheticmethodologystartingfroma-santonin2e.Ourinterestofstudyonthesynthesisof…     

A Facile Synthesis of 4-(3β -Methoxy-5α-androstan-17β-YL)-3-pyrrolin-2-one

The title compound was prepared in 4 steps from 3β-methoxy-21-hydroxy-5α-pregnan-20-one (1). The required intermediate (4) was obtained using lithium enolate derived from t-butyl acetate. Interesting enough, p-tosyl chloride in pyridine quantitatively converted compound 1 into the α-chloro ketone derivative (2).     

The First Total Synthesis of Natural 6β-Cinnamoyloxy-1α- hydroxy-5, 10-bis-epi-eudesm-4-en-3-one

Eudesmane and agarofuran are naturally occurring sesquiterpenoids with characteristic decalin skeletons. These natural products frequently contain multiple hydroxyl groups and contiguous stereocenters. Members from these families show cytotoxic, immuno- s…     

Synthesis of ( )-5α-Hydroxy-β-selinene and (-)-5β-Hydroxy-β-selinene

Eudesmanederivativeshavebeendrawingconsiderableattentionduetotheirwidespectrumofbiologicalproperties,particularlyantifeedant,cellgroWthinhibitoryandplantgroWthregulatingactivitiesl'2.Recently,twoepimericeudesmanederivatives( )-5a-hydroxy-6-selinene1and(-)-56-hydroxy-6-selinene2wereisolated3fromtheaerialpartsofCSubtraPicaFMell.,andtheirstructuresweredeterminedbyspectroscopicmethods.Herein,wereportafacilesynthesisofbothtwodiastereomers1and2from( )-dihydrocarvone3infivesteps,usingtheregioselect…