Circular Dichroism Spectra of Stigmastane 3β-Benzoyloxy-6-ketosteroids

CD spectra of stigmastane derivatives containing a 3-benzoyloxy group and a saturated or conjugated 6-ketone were studied. Application of known empirical rules to functional groups enabled the mutual influence on the optical activity of their electronic transitions in the compounds to be evaluated. It has been demonstrated that CD spectra can be used to prove the structures of these steroids.     

Synthesis and Dehydrohalogenation of 3 β-Chloro-5 α,7 α-dibromo-6-ketosteroids of the Stigmastane and Cholestane Series

3-Chloro-5,7-dibromo-6-ketosteroids 5a and 5b are synthesized from -sitosterol (1a) and cholesterol (1b). Dehydrohalogenation of these forms 7-bromo-2,4-dien-6-ones (6a-b), 2,4-dien-6-ones (7a-b), and 14-hydroperoxy-2,4,7-trien-6-ones (8a-b). Woodward hydroxylation of dienone 6a produces 2-iodo-7-bromo-3-acetoxy-⁴-6-ketone 9 and 7-bromo-2,3-diacetoxy-⁴-6-ketone 10. 2-Iodo-3-acetoxy-^4,7,14-trien-6-one 11 is prepared analogously from trienone 8a.     

Structural Dependence of Insecticidal Activity of 5α-Hydroxy-Δ7-6-ketosteroids

The toxicity of 5-hydroxy- ⁷ -6-ketosteroids for colorado beetleLeptinotarsa decemlineataSay. larvae was studied by topical and GI administration.     

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…     

Synthesis of 2β, 3β, 14α-trihydroxy-Δ4,7-6-ketosteroids and their derivatives

A scheme using -sitosterol as an example for synthesizing 2, 3, 14-trihydroxy-^4,7-6-ketosteroids and their derivatives from 3-hydroxy-⁵-steroids was developed.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141, Belarus, Minsk, ul, akad. Kuprevicha, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 244–248, May–June, 2000.     

Novel Synthesis of 5-Hydroxy-5α-cholesta-2,7-dien-6-one and Its Criegee Hydroxylation

Cholesterol (1) is used to synthesize again 5-hydroxy-2,7-dien-6-one (5) through the intermediates 2-4. cis-Hydroxylation of 5 with OsO ₄ and subsequent acetylation give steroids 6-8. Dehydration of 5-hydroxy-6-ketone 6 forms the unsaturated compounds 9-11     

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.     

Synthesis of 5-O-β-Iodoethyl-D-Glucofuranose

ABSTRACT

The preparation of an iodinated derivative of D-glucose where a β-iodoethyl moiety has been introduced at O-5 is presented. In such an analogue the existence of pyranose forms is precluded and the iodinated tag lies in a region of the carbohydrate not judged essential for recognition by the glucose transport protein; also noteworthy in such a compound is the stability of the carbon-iodine bond, a prerequisite for its potential use in SPECT medical imaging.     

Stereoselective Synthesis of α-Methylene-β-Hydroxy-γ-Alkoxy Esters and Ketones

The amine catalysed aldol-type addition of vinylcarbonyl units to α-alkoxy aldehydes proceeds with reasonable diastereoface selectivity to afford the title compounds in good yield.     

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…     

Facile Synthesis of 5-Hydroxy-2-（2-phenylethyl）chromone

5-Hydroxy-2-(2-phenylethyl)chromone(1) was synthesized from 2,6-dihydroxyacetophenone(7) obtained via four-steps resorcinol-reacting with phenylpropionic acid,the procedures involved are Baker-Venkataraman rearrangement and cyclization which are easy to conduct,the overall yield is 32%.     

Synthesis of 6β-Halogenodeoxyneopine from Neopine

(-)-Neopine (1), the Δ^8,14 isomer of codeine, occurs as one of the minor constituents in opium from Papaver somniferum L¹. In opium alkaloids of the morphine group the hydroxyl group in position 6 is readily converted with p-toluenesulfonyl chloride or methanesulfonyl chloride into the respective 6α-O-sulfonyl derivatives². The latter in turn form starting materials for the preparation of other derivatives. Thus, with lithium halides, via a S_N2 mechanism³ the 6β-halogen compounds are formed. It is found that, as a result of the allylic system, under slightly changed reaction conditions codeine itself can also yield the 8β-chloro derivative⁴.     

Synthesis of Trideuteriomethyl 5-Deuterium-β-D-Mannopyranoside

Abstract

The title compound was prepared by first converting trideuteriomethyl 2,3,4-tri-O-benzyl-β-D-mannopyranoside to a 6-bromo-6-deoxy derivative which on elimination by using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or DBN (1,5-diazabi-cyclo[4.3.0]non-5-ene) gave a hex-5-enopyranoside derivative. The deuteroboration of the hex-5-enopyranoside followed by oxidation and subsequent deblocking produced trideuteriomethyl 5-deuterium-β-D-mannopyranoside.     

Synthesis of oligo-6-bromo-6-deoxy-β-cyclodextrins

Two methods of synthesis of oligo-6-bromo-6-deoxy--cyclodextrins, with use of the Vilsmeier-Haack reagent and via tosyl derivatives of -cyclodextrin, were compared. The second method holds more promise, since it allows a desired number of bromine atoms to be introduced into the -cyclodextrin molecule instead of hydroxy groups. A correlation between the decomposition onset points of oligo-6-bromo-6-deoxy--cyclodextrins and the number of bromine substituents in them was revealed.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1743–1745.Original Russian Text Copyright © 2004 by Kurochkina, Trushkin, Grachev, Nifantev.This revised version was published online in April 2005 with a corrected cover date.     

Efficient Synthesis of Indolizidine Alkaloids from γ-Hydroxy-α,β-unsaturated Sulfones

An efficient and stereoselective synthesis of polyhydroxylated indolizidine alkaloids from readily available N-substituted γ-hydroxyvinyl sulfones is described.     

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 new α-chloropyridine derivatives of steroidal 3β,5α,6β-triols and 3β,5-dihydroxy-6-ketones

New steroid derivatives containing 6-chloropyridine groups characteristic of the alkaloid epibatidine and neonicotinoid insecticides were synthesized by reacting 3β,5α,6β-trihydroxysteroids or 3β,5-dihydroxy-6ketosteroids with 2-chloro-5-chloromethylpyridine. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 180-182, March-April, 2009.     

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

Eudesmane derivatives have been drawing considerable attention due to their wide spectrum of biological proerties, particulaly antifeedant, cell growth inhibitory and plant growth regulating activities.¹ In recent years a number of C-6 oxyfunctionalized eudesmanes and β-dihydroagarofurans,such as compounds 3-6,have been isolated from nature sources. However the reports on the synthesis of this particular kind of compounds are few and the reported syntheses are generally by synthetic methodology starting from α-santonin 2². Our interest of study on the synthesis of this kind of compounds prompted us to investigate a new synthetic route from cheap material (+)-dihydrocarvone 7.     

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).