2-Methyl methylamid

Phenylalanin (S)-2-Methyl- -methylamid E16d. 458 (Ring-spalt.)... 

The importance of ring size holds also for tautomerism of -pyrrol-5-ones and. d -dihydro-6-pyridones. While the former compounds behave as cyclic 1-methyl-2-alkyl-2-hydroxy-5-pyrrolidones 179) (76) [or, on distillation, as the dehydrated l-methyl-2-alkyl-J -pyrrolones (77)], the latter compounds exist as acyclic N-methylamides of 8-oxo-acids (78) [as shown by infrared spectroscopy (/80)j. The dehydration of 78 during distillation to form l-methyl-2-alkyl-. -dihydro-6-pyridones (79) is achieved only with difficulty. 

With 1-hydroxytryptophan derivatives, similar substituent effects are observed (99H2815). In order to realize better yields of 5-substituted tryptophans, car-boxy and amino groups are transformed to ester and/or amide groups, choosing the 1-methoxy moiety as a leaving group. As a result, ( )-Ab-acetyl-5-chlorotryptophan methyl ester (219, 52%) is obtained together with 220 (7%) from ( )-218 by the reaction with aqueous HCl (Scheme 32). ( )-5-Bromo-Ab-methoxycarbonyltryptophan methylamide (222, 50%) becomes readily available... 

The completion of the synthesis of the polyol glycoside subunit 7 requires construction of the fully substituted stereocenter at C-10 and a stereocontrolled dihydroxylation of the C3-C4 geminally-disub-stituted olefin (see Scheme 10). The action of methyllithium on Af-methoxy-Af-methylamide 50) furnishes a methyl ketone which is subsequently converted into intermediate 10 through oxidative removal of the /j-methoxybenzyl protecting group with DDQ. Intermediate 10 is produced in an overall yield of 83 % from 50) , and is a suitable substrate for an a-chelation-controlled carbonyl addition reaction.18 When intermediate 10 is exposed to three equivalents of... 

N-(benzyloxycarbonylglycyl)-, methyl ester N-(8-methoxycarbonyloctanoyl)-, methylamide methylamide 2-acetamido-2-deoxy-N-acetyl-... 

L-alanylglycyl-L-cysteinyl-L-lysyl-L-asparaginyl-L-phenylalanyl-L-phenylalanyl-L-tryptophanyl-L-lysyl-L-threonyl-L-threonyl-L-cysteine 6-0-benzoyl-N-(benzyloxycarbonyl) methylamide 4,6-0-benzylidene-N-benzylidene-N-(benzyloxycarbonyl) methylamide N- (benzyloxy carbonyl) -N-(benzyloxycarbonyl)-, amide N-(benzyloxycarbonyl)-, hydrazide N-(benzyloxycarbonyl)-, methylamide N-(benzyloxycarbonyl)-, methyl ester N-(benzyloxycarbonyl)-L-alanyl-L-alanine methyl ester N-(benzyloxycarbonyl)-L-alanylglycine ethyl ester N-(benzyloxycarbonyl)glycyl-L-alanine methyl ester 3,4,6-tri-0-acetyl-2-amino-2-deoxy-N-(benzyloxycarbonyl)-, benzyl ester, hydrochloride... 

This view has been challenged with more recent evidence indicating that AT-[(acyloxy)methyl] derivatives of both primary and secondary amides (8.170, Fig. 8.21) undergo decomposition by the same mechanisms, namely a) an acid-catalyzed process involving protonation followed by formation of an /V-acyliminium species (Fig. 8.21, Reaction a) b) a pH-independent heterolytic cleavage forming the same /V-acyliminium species (Fig. 8.21, Reaction b) and c) a base-catalyzed pathway, which for /V-[(acyloxy)methyl] derivatives of AT-methylamides is the normal mechanism (Fig. 8.21, Reaction c), but for AT-[(acyloxy)methyl] derivatives of primary amides involves substrate deprotonation followed by /V-acy limine formation (Fig. 8.21, Reaction d) [218],... 

Many NRPs such as cyclosporin, complestatin, actinomycin, and chondramide contain N-methyl amides. M-Methyl transferase (N-MT) domains utilize S-adenosylmethionine (SAM) as a cofactor to catalyze the transfer of the methyl group from SAM to the a-amine of an aminoacyl-S-PCP substrate. The presence of M-methylamides in NRPs is believed to protect the peptide from proteolysis. Interestingly, N-MT domains are incorporated into the A domains of C-A-MT-PCP modules, between two of the core motifs (A8 and A9). MT domains contain three sequence motifs important for catalysis. ° 0-Methyl transferase domains are also found in NRPSs and likewise use the SAM cofactor. For instance, cryptophycin and anabaenopeptilide synthetases contain 0-MT domains for the methylation of tyrosine side chains. These 0-MT domains lack one of the three core motifs described for N-MT domains. ... 

In Einzelfallen bietet sich die Ugi-Reaktion fur die Synthese bestimmter a-Amino-carbonsauren im Vergleich zu anderen Moglichkeiten als Methode der Wahl an. Beispiele sind die Herstellung von Bis-[l-carboxy-alkyl]-aminen I aus a-Amino-carbonsaure-estern8 [unter Verwendung von 4-Methyl-phenylsulfonylmethyl-isocyanid (TOSMIC)9 als Isonitril-Komponente] und die von 3-(2,5-Cyclohexadienyl)-alanin-methylamid(ll) (37% aus 3-Formylmethyl-l,4-cydohexadien)1. 

Umsetzung von 1-Brom-alkanen mit N-Benzyl-hydroxylamin in Phosphorsaure-tris-[di-methylamid] (HMPT), Dehydratisierung des so gebildeten N-Alkyl-N-benzyl-hydroxyl-amins mit 2-Fluor-l-methyl-pyridinium-(4-methyl-benzolsulfonat) und saure Hydrolyse des entstandenen N-Benzyliden-amins ergibt 1-Amino-alkane in guten Ausbeuten3. 

From the archival enthalpies of formation of the other species, the enthalpy of formation of cyclohexyl methyl amine is —145.4 kJmoH. From equation 11, the enthalpy of formation of the corresponding salt is —501.2 kJmoH. Attempts to estimate an enthalpy of formation for A-methyldodecanamide reveals a paucity of data to work with, primarily for unsubstituted and A-methylamides . There is much enthalpy of formation data for w-alkyl carboxylic acids, including dodecanoic acid. The methylene increment... 

LXVI 6-Acetamido- 3-methyl- capronsaure- methylamid 10 20- 2 2 200,3 Chloro- form 0,46 25 589 +24,57... 

Rates of hydrolysis of several substrates in water and in D20 have been compared (9). Average values of Vh2o/Vd2o were, for glutamine, 1.16 for methyl glutamate, 1.38 for glutamyl methylamide, 1.10 and for glutamic acid, 1.50. 

Hersh et al. 133) have studied an enzymic reaction between methyl-amine and a-ketoglutarate which is catalyzed by cellfree extracts of a Pseudomonas the product of this reaction was shown to be 5-hydroxy-iV-methylpyrrolidone carboxylic acid. Although the mechanism of this reaction is not as yet understood, it was suggested that the synthesis of 5-hydroxy-iV-methylpyrrolidone carboxylic acid involves two steps. The first of these is presumably enzymic and leads to the formation of the y-Af-methylamide of a-ketoglutaric acid ... 

Azobis(methylformamide) or Azodicarboxy-methylamide (called Azodicarbonsaure-bis-methylamid in Ger), HjC NH CONtN CONH— CHj, mw 144.14, N 38.87% yel powd, mp 170° (decomp). Its salts are not mentioned in Refs 1 St 2 (below) but it seems possible that its Ag salt might be prepd in the manner described for the prepn of the Ag azobis-ethylformamide salt in Ref 2, p 2006 (above). Since the Ag salt of the ethylamide is expl, it is likely that the Ag salt of the methyl-amide would also be expl... 

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