
doubleu. clark ajunahi

william clark still (janm 1946) haah eka american sendriya rasayanshastradnya aahe. kolambiya vidyapithat eka pratishthit pradhyapak mhanoon, clarkney ajunahi sendriya rasayanshastra kshetrat, visheshtah naisargik utpadan sanshleshan, pratikriya vikas, sanrachanatmak vishleshan, sthoolchakriy stereocontrol aanee sanganakeey rasayanshastra yaa kshetranmadhye mahattvapoorn yogdan dile aahe. sthir aanee sahakanyanni flash collum chromatography mhanoon olakhale jaanare shuddhikaran tantra dekhil vikasit kele jeey sendriya sanyuganchya shuddikaranasathi mothya pramanat vaparale jaate.
mothe yogdan.
ekoon sanshleshan.
periplanone bii.
1979 madhye, ajunahi american telgoojcha shaktishali seeks ferromon, periplanone bii chey pahile ekoon sanshleshan nondavale gele. jaree yaa sanyugachi sanrachanatmak jodani spectroscopic paddhatine sthapit kelee gelee asali taree, tarihichya sanshleshanane yaa naisargik utpadanat upasthit asalelya sapeksh stereochemical sambandhanchi pushti kelee. yaa sanshleshanatil eka mahattvachi payari mhanje periplanone bii madhye aadhalanari macrocyclic 10-sadasyanchi ring tayar karnyasathi ionic auxi -scope punvyavastha. yaa parivartanat, prarambhik trutiyak alcoholver potassium hydride aanee 18-kraun-6 neey uchch tapmanavar prakriya karoon punvyavastha prerit kelee gelee aanee parinami annolet chlorotrimethylacylane adakoon ekeri diasteriomer mhanoon macrocyclic silil inol ether tayar kele gele. rubotum auxidation, duyyam alcoholche tii. bii. ess. sanrakshn aanee selenoxide punarrachanedware exocyclic alkin tayar karane yasah paach tappyanchya kalavadhit yaa madhyavartiche rupantar eka pramukh inon tharat karnyat aale.
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yaa parivartananni donhi epoxide gatanchya parichayasathi tappa nishchit keela, jeey macrocyclic stereocontrolchya tattvanvar aadharit uchch patalichya diasteriocelectivitis tayar jhaale hote. potassium hydride aanee turt-beautylhydroperoxide vapar karoon inonechya nucleophilic epoxidationdware pahile epoxide sadar kele gele; yamule diasteriomeric epoxideche 4:1 mishran tayar jhaale, jeey ichchit isomerchya bajoone hote jyamadhye inonechya paridhiy chehyapasun hallah jhaala hota. yaa tappyavar, johnson-corey-chekovsky abhikriyecha vapar karoon keatoneche dusya epoxide gatamadhye rupantar karnyat aale; visheshtah, kitonvaril diamethylosulphonium methyloid nucleophilechya prarambhik paridhiy hallyamule, utpadan ekach diasteriomer mhanoon tayar jhaale. tyanantar sanrakshn gut tii. bii. ess. kadhoon takane aanee parinami duyyam alcoholchya sarrett oxidationane resmick periplanone beeche ekoon sanshleshan purn kele.
monesin.
1980 madhye, sthir aanee sahakanyanni ionophore mhanoon kaam karnare eka jatil polyether naisargik utpadan, monesinache ekoon sanshleshan nondavale. yaa margavaril eka pramukh payari mhanje aantaraanvik eldol abhikriyedvare done pragat tukadyanche shevatchya tappyatil millen. yaa abhikriyemadhye, lithiyam dysopropylamides methyl keatoneche qamee-tapmanatil apbhranshane gatij annolet tayar jhaale jeey nantar magneshiyam bromidechya jodaninantar transmatelation jhaale. tyanantar eldehyde ghatakachya jodanimule diasterioselective eldol pratikriya suru jhaali, jyamule diasteriomers 3:1 mishran mhanoon 75 takke utpadanat ichchit beeta-hydroxicatone tayar jhaale. vishesh mhanje, acyclic stereocontrolche heey udaharan alfa sthiteet vidyaman stereocenter asalelya eldehydemadhye nucleophiles jodanyasathi cram-felkin-nh modelshee susangat aahe.
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<bii. aar.> <bii. aar.> 
heey done guntaguntiche tukade ekatra karoon, tarihi teen atirikt payyanmadhye monesinache sanshleshan purn karnyat saksham hote. pratham, benzil samoohachya hydrogenolysismule pramanit paristhitit mofat prathamik alcohole miloo shakale. pudhe, trithylacylil (tess) sanrakshn gatanchi vighatana parra-toluensulphonic aesidchya upasthitit sadhya jhaali; parinami mukt duyyam alcohole nantar thermodynamic spirocatal linkage tayar karnyasathi ketonla utsfurt chakriy pratikriyemadhye guntavatat. shevati, moolbhut paristhitit methyl esterchya jalvichhedanane, yaa aavhanatmak naisargik utpadanache sanshleshan purn karoon, monesinache soodiyam meeth tayar kele.
paddhat vikas.
whittig-still punarrachana.
2, 3-whittig punvyavastha hii eka upayukt carbon-carbon bandh tayar karnari pratikriya aahe jee elil etherche samdharmi alcoholmadhye rupantar karate. tathapi, yaa abhikriyechi eka lakshaniy maryada mhanje alcoxy-pratisthapit carbenian tayar karnyatil adchan jee 2,3-sigmetropic punarrachanechi suruvat karate. paramparikpane, yasathi eather tharanche deprotonation saksham karnyasathi majboot payacha vapar aanee sthir gut asane aavashyak hote. 1978 madhye, alcoxy-pratisthapit carbeniancha purvavarti mhanoon organotin-pratisthapit eather sadar karoon 2,3-whittig punarrachanechi vyapti ajunahi natyamayaritya vadhavali. yaa prakriyet, organotin samoohache transmatelation aine-butylithiumcha vapar karoon qamee tapmanat rasayanik nivadak paddhatine sadhya kele jaau shakate, jyamule alfa-lithiate eather tayar hoto, joou ichchit 2,3-sigmetropic punarrachanetun jaato. paramparik 2,3-whittig abhikriyechya yaa badalala whittig-still punvyavastha mhanatat. <bii. aar.>
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naisargik utpadan sanshleshanachya sandarbhat whittig-still punarrachanecha vapar, secropia kishore samprerkachya 1979 chya sthir aupcharik sanshleshanat disun yeto. punarbandhanisathi thurr mhanoon kaam karnara organotine-pratisthapit eather iodomethyltribution sambandhit diolchya biis-alkayaleshandware sahajpane tayar keela gela. qamee tapmanat 'aine'-butylithiumchya done samatulya asalelya yaa sanyugavar kelelya upcharanmule transmatelation jhaale, jyamule bayas-homaliclic alcohole utpadanache 79 takke utpadan denyasathi duppat 2,3-sigmetropic punarrachana suru jhaali. vishesh mhanje, hii punarrachana trisbustituted olephinachya bhoomitichya sandarbhat atyant stereoselective aahe, jeey keval ("zed", "zed")-isomer darshavate.<bii. aar.>
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sthir-jenari alcanation.
horner-wadsworth-emmons pratikriya hii eka mothya pramanavar vaparali jaanari olephination pratikriya aahe jyamadhye phosphonet-sthir carbenian aldehyde kinwa keatones pratikriya deuun alkin tayar karate. manak mankyanchya abhikriyemadhye, phosphonet estermadhye alcoxy paryay (samanyatah methoxy kinwa ethoxy) asatat, jeey pramukh utpadan mhanoon "eae"-alkin tayar karatat. 1983 madhye, sthir aanee genarine nondavale qee phosphonet ghatkavar adhik electron-kadhanare 2,2,2-trifluoroethoxy gut badaloon stereoselectivitaly pramukhyane "zed"-alken tayar karnyasathi ulat kele. uchch patalichya "zed"-nivadaktela samanvay naan karananya pratibandhacha vapar dekhil mahattvapoorn asalyache aadhalun aale; heey samanyatah 18-mukut-6 chya upasthitit potassium pratibandhacha aadhar vaparoon purn kele jaate. ektritpane, yaa protocolla horner-wadsworth-emmons pratikriyecha sthir-jenari badal kinwa, vaikalpikaritya, sthir-jenari olephination mhanoon olakhale jaate. 
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yaa abhikriyechi yantrana jaree purnapane spasht keleli nasali taree, assa andaj vartavala jaato qee electron-kamatarata asalelya phosphonetchya vaparamule oxphosphaton madhyavarti nirmulanala gatee milate. yamule phosphonet-sthir carbenianchi eldehydemadhye prarambhik bharr padane prabhavipane aparivartaniy hote, jyamule pramanit whittig abhikriyechya sadrushyat "zed"-nivad hote.
flash collum chromatography.
1978 madhye, sthir aanee sahakanyanni flash collum chromatography mhanoon olakhalya jaanarya shuddhikaran tantracha ahwal denara eka atyant prabhavshali pepper prakashit keela. yaa ahavalachya aadhi, silika jailcha sthir tappa mhanoon vapar karoon stambh chromatography hii sendriya sanyuganche pruthakkaran aanee shuddhikaran karnyasathi eka maulyavan paddhat mhanoon aadhich sthapit kelee gelee hotee. tathapi, keval gurutvakarshanadvare dravkache nishkasana hii anekada eka kantalvane prakriya hotee, jyasathi anek taas lagatat aanee prasaradvare pattya rund jhalyamule kharab pruthakkaran hote. dravak utsarjanacha veg vadhavanyasathi stambhachya varchya bhagavar dabav aanane haah sthiratecha navkalpana hota. yamule stambh chalvanyasathi lagnara vel keval mothya pramanat qamee jhaala nahee, tarr 0.10 kinwa tyahoon adhik aar. eff. farak asalelya sanyuganna niyamitpane vegale karanyachi parvanagi midali. hii prakriya anukool kelyanantarhi, prayogshalet yaa tantrachya vaparasathi upayukt margdarshak pradan karat, stambh vyas, alootche praman, namunyache praman aanee vishisht apurnank aakar yancha parasparsambandh asaleli eka sarani sankalit kelee. aaj, sendriya sanyuganchya shuddikaranasathi flash collum chromatography hii sarvat mahattvachya paddhatinpaiki eka aahe, visheshtah jevha teey chhotya pramanat (<50 mii. gra.) kaam karatat, jethe punarprakriya aanee aasavan tantra avyavharya asate. flash collum chromatography varnan karnara steelcha pepper heey tyache sarvat jaast uddhrut kelele prakashan aahe aanee 35 varshanpurvi prakashit hounahi, 'journal auph organic chemistry' madhoon sarvadhik vela download kele jaanare pepper asanyacha gaurav aahe.
sanganakeey rasayanshastra aanee macromodel.
krutrim sendriya rasayanshastratil tyanchya yogdanavyatirikt, clark heey sendriya sanyuganchya abhyasasathi sanganakeey paddhati lagoo karnyat ajunahi eka prarambhik pranete hote. sthirpane kelelya sthoolchakriy stereocontrolchya abhyasasathi sanrachanatmak vishleshan haah avibhajya bhag hota aanee sendriya renuchya sarvat qamee urja sanrachanecha andaj lavnyasathi vegwan aanee vishvasarh sanganakeey paddhatichi sarvasadharan garaj hotee. yaa samasyeche nirakaran karnyasathi, sthir aanee sahakanyanni 1989 madhye sanrachanatmak jaaga shodhanyasathi eka sadhee monte carlo paddhat nondavali. yaa prakriyet, sendriya renusathi antargat nirdeshank yadruchchikpane badalale gele aanee sanrachana qamee kelyanantar sarvat qamee urja sanrachanechi urja nirdharit kelee gelee. pratyek punaravruttinantar, jaagtik kiman shodhanyasathi kiman urjechi tulana purvi midavalelya mulyanshi kelee gelee; tarihi yaa ekoon prakriyecha sandarbh monte carlo multiple-minimum search assa deela jaato.
sendriya rasayanshastradnyansathi aanvik modelling adhik sulabh karnyachya prayatnat, tarihi 1986 madhye kolambiya vidyapithachya sahkaryane ekatmik software program macromodel vikasit keela. dow. tyaa velee steelchya gatatil varishtha postdoctoral sanshodhak wein guida yanni yaa software package vikasache varnan khaleel prakare keleh 
sthool pratikrutiche eka vishesh lakshaniy vaishishtya mhanje jee. bii./ess. aii. (samanyikrut janmalele pratikruti, jyamadhye hydrophobic dravak sulabh prushthbhag kshetrachya sandnyesah vaadh kelee gelee) mhanoon olakhale jaanare antarbhut dravan pratikruticha samavesh. jee. bii./ess. aii. modelane sangananat spasht vaiyaktik dravak renuncha samavesh karnyaivaji satat dravak kshetra samavisht karoon sendriya renunshi dravak parasparsanvadache anukaran kele. 1990 madhye ganan rasayanshastra niyatkalikat macromodelche sampoorn varnan ajunahi ughad kele gele aanee yaa softwareche adhikar nantar schroedinger, ink. neey midavale. 1998 madhye.