L nitril

L-Amino adds could be produced from D,L-aminonitriles with 50% conversion using Pseudomonas putida and Brembacterium sp respectively, the remainder being the corresponding D-amino add amide. However, this does not prove the presence of a stereoselective nitrilase. It is more likely that the nitrile hydratase converts the D,L-nitrile into the D,L-amino add amide, where upon a L-spedfic amidase converts the amide further into 50% L-amino add and 50% D-amino add amide. In this respect the method has no real advantage over the process of using a stereospecific L-aminopeptidase (vide supra). 

Though borazine itself gives no stable complexes, alkyl substituted derivatives are formed by the reaction of borazines with LjMfCO), (L = nitrile) (Table 1,... 

It is worthy to note that four of the eight possible diastereomeric pyrrolidine-polyols are accessible by this method. The configuration at C(l) (nitrile oxide part) depends on the enantiomeric aldehyde precursor chosen. The 5-epimers were obtained as a separable 1 1 mixture and were derived from the nonselective cycloaddition (see Section 6.2.3.4). 

Nitriles Citralva(geranylnitrile) (cis-3,7-dimethyl-2,6-octa-dicne-l-nitrile) C1(iH,5N 0.048 0.050 17... 

Natriumenolate sind der Reaktion ebenfalls zuganglich. So erhalt man beispielsweise aus Ethan-thiophosphonsaure-chlorid-O-ethylester und dem Natriumsalz des 3-Oxo-bern-steinsaure-4-methylester-l-nitrils den Ethan-thiophosphonsaure-0-(2-cyan-l-methoxy-carbonyl-vinylester)-0-ethylester (67% Sdp. 13570,01 Torr/1,3 Pa)792 ... 

Methyl-propanoyloxy)-2-oxo-E14a/2, 303 (Enoi-ester + Cl — S02 — NCO/Hydrolyse) Bernsteinsaure 2-Hydroxy-2-methyi- -4-ethylester-l-nitril E5, 1417 (On HCN)... 

Carbonyl group, apeeifle i.r. abaorpUon of, m laetonea, 770 Oarbot l nitrile, reaction with aoetio... 

Isomer shifts in the Mossbauer spectra for SbClj,L, where L = nitrile,749 OPCl3, OPR3, DMF, Cl-,750 etc., have been interpreted to show an order of donor power for the ligands. Vibrational assignments and normal-coordinate analyses have been reported for SbCls,DMSO and SbCl5,[2H6]-DMSO.75 ... 

Site selectivity in a number of other concerted cycloadditions which are not [4 + 2] cycloadditions is also explained by frontier orbital control. Thus diphenylketene (332) reacts with isoprene (333) mostly at the more substituted double bond, and with cis-butadiene-l-nitrile (334) at the terminal double bond.263 Dichlorocarbene reacts at the terminal double bond of cycloheptatriene (335),264 and the Simmons-Smith reaction (336 + 337)265 also takes place at the site with the higher coefficients in the HOMO. 

Aminocarl )onyl-2,2-dimcthyl-l-(2-methyl-l-propenyl)- 1789 1 -Methyl-2-morpholino-l -vinyl- 130 I lexan-6-al-l -nitrile... 

Site selectivity in ketene cycloadditions is also explained by the frontier orbitals. Diphenylketene reacts with isoprene 6.397 mostly at the more substituted double bond to give the cyclobutanone 6.398 as the major product.890 In contrast, it reacts with cw-piperylene 6.399891 and with cw-butadiene-l-nitrile 6.400890 at the less substituted double bond. In all three cases the site of attack is the double bond having the largest coefficient in the HOMO. 

Studies of the geometry of intramolecular contacts between nucleophilic O and N atoms and the sp C and N electrophilic centers were undertaken in a direct and straightforward extension of the earlier investigations of aminoketones and amino-acid derivatives. Four structures, namely 8-methoxy- and 8-nitronaphtho-l-nitrile (Scheme 6.9, structures 2 and 3) [98], quinoline-8-diazonium-l-oxide... 

The very different redox potentials for cis- and ra s-[M(CO)2(L-L)2] and the isomeric preference shown in each redox state have been rationalized by MO calculations on [MoL2(PH3)4]. Strong n acceptors (e.g., L = CO) stabilize the neutral cis and the cationic trans complexes whereas the trans isomer is preferred in both cases when strong donors (e.g., L = O2-) are present 108). Interestingly, 7s-[Mo(CO)(NOXdppe)2] + is isomerized on oxidation 36) whereas [ML(NO)(dppe)2]z(M = Moor W), with one strong n acceptor (NO) and one a donor (L = halide, Z = 0 L = nitrile, Z = 1), retain the trans geometry on electron loss 36,109). 

Startg. m. prepared from 2-benzoyl-l,2-dihydroisoquinaldo-l-nitrile and 48%-HBF4 in glacial acetic acid according to Am. Soc. 93, 4479 (1971) (Y 90%) mixed with ethyl acrylate and methylene chloride, refluxed with slow addition... 

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