5-Mcthyl-2- -methyl

Ethoxycarbonyl-2-(methoxy-mcthyl)- -methyl- 2735 Cyclopropenone Diisopropyloxy- 2997 2,9-Dioxa-bicyclo[4.3.0]nonane... 

Blasticidin S is an antibiotic of pyrimidine type, discovered in 19SS in the metabolites of Streptomyces griseochromogenes Fu i imgpetal., 1955). Blastiddin S, soluble in water, appears in the form of white needles. Its structure was eluddated by Yonehara and Otake (1966) S-[4-[3-amino-5-[(amino-imino-mcthyl)-methyl-amino]-1 -oxopentylj-amino]-1 -[4-amino-2-oxo-1 (2H)-pyrimidinyl]-1,2,3,4-tetrade-oxy- -D-er/7rohex-2-ene pyranuronic acid (9). 

To return to a more historical development the mercuric acetate oxidation of substituted piperidines (77) should be discussed next. This study established that the normal order of hydrogen removal from the aW-carbon is tertiary —C—H > secondary —C—H > primary —C—H, an observation mentioned earlier in this section. The effect of substitution variations in the piperidine series can be summarized as follow s l-mcthyl-2,6-dialkyl and 1-methyl-2,2,6-trialkyl piperidines, as model systems, are oxidized to the corresponding enamines the 1,2-dialkyl and l-methyl-2,5-dialkyl piperidines are oxidized preferentially at the tertiary a-carbon the 1-methyl-2,3-dialkyl piperidines gave not only the enamines formed by oxidation at the tertiary a-carbon but also hydroxylated enamines as found for 1-methyl-decahydroquinoline (48) (62) l-methyl-2,2,6,6-tctraalkyl piperidines and piperidine are resistant to oxidation by aqueous mercuric acetate and... 

The corresponding reaction with 2-methylamino-5-nitroaniline affords an unambiguous synthesis of l-methyl-6-nitroquinoxaIin-2-one, the A -mcthyl derivative of (6) this product is also obtained by treatment of (6) with methyl iodide and methanolic sodium methoxided ... 

If the carbonyl grou]) in the 3-position of N-methylisatin or tlii-ana])hthencquinone is blocked by formation of an oxime (cf. 112), A -methylation of the oxime group occurs instead of ring expansion on reaction with diazomethane. In methanol, thianaphthenequinone oxime iV-mcthyl ether (113) then undergoes ring opening catalyzed by diazoniethane (113 114). 

Bromination of 7-ter/-butyl, 2-mcthyl 5-methyl-4//-azepine-2,7-dicarboxylate (7) with 1 equivalent of jV-bromosuccinimide yields 2-terf-butyl,7-methyl 4-(bromomethylene)-4,5-dihvdro-l//-azepinc-2,7-dicarboxylate (8) as a 1 2 mixture of the E- and Z-isomers.113 With an excess of reagent the dibromomethylene compound 9 results. 

Benzoyl-l-methyl-3,4-benzo-2-azabicyclo[3.2.0]hepta-3.6-diene (3) at 250"C yields exclusively l-benzoyl-2-mcthyl-l//-l-benzazepine (4).23 In contrast, silvcr(I) ion catalyzed ring expansion of 3 yields a mixture of the rearranged bicycle 5 (43 %), starting material (43 %), and the isomeric 1 H-l-benzazepines 4 (8%) and 6 (4%).23... 

Occasionally, these thermally induced reactions give rise to complex mixtures of products and hence are not of any great preparative value. For example, 1-mcthylindolc with dimethyl acetylenedicarboxylate in acetonitrile yields seven products including the 1-benzazepine 8 (14%), the 1-methyl derivatives of the cis- and /rwK-indolylacrylates 3. a [4 + 2] cycloadduct of the 1-benzazcpinc with the alkyne dicster (see Section 3.2.2.5.3.), and dimethyl l-mcthyl-2-(l-methylindol-3-yl)-2,3-dihydro-l //-l-benzazepinc-3,4-dicarboxylate (9).21 This last product, which is the major product if the cycloaddition is carried out in acetonitrile containing trace amounts of water,21 has been obtained earlier.143 but was incorrectly formulated. 

Curiously, the ring expansion fails in sulfuric, trifluoroacetic, trichloroacetic, and orthophos-phoric acid. The reaction is sensitive to substituents both in the TV-aryl group and in the 2-and 3-positions of the indole nucleus. For example, 3-methyl-l-phenylindole yields a mixture of 10-methyl-5//-dibenz[/t,/]azepine (34% mp 129-131X) and 2-mcthyl-l-phenylindole (57%). In contrast, 2-methyl-l-phenylindole and 2,3-dimethyl-l-phcnylindole fail to ring expand. The reaction also fails with electron-withdrawing groups (N02 and CF3) in the TV-phenyl ring. 

Mcthyl-5//-dibenz[/>,/ azepinc 5-oxidc (3) is deoxygenatcd rapidly and in high yield to 5-methyl-5//-dibenz[/>,/]azepine (4) by aqueous sodium sulfite, and, less efficiently and accompanied by deniethylation, by heating at 160-170 C for 20 minutes.124... 

Racemic l-methyl-2-butenylboronates (E)- and (Z)-3 may be prepared selectively via reactions of the l-methyl-2-butenyl Grignard reagent with the appropriate borate ester. Use of triisopropyl borate provides a 96 4 mixture of (E)-3l(Z)-3 on a 0.36 mol scale15. Use of a bulkier borylating agent, such as 2-isopropyloxy-4,4,5,5-tetramethyl-l,3,2-dioxaborolane, reverses the selectivity, enabling a 91 9 mixture of (Z)-3/( )-3 to be obtained on a 0.5 mol scale. The diastereomeric purity of this mixture may be enhanced to 95 5 by treatment with 0.15 equivalents of benzaldehyde, since ( )-l-mcthyl-2-butenylboronatc ( )-3 is more reactive than (Z)-3. Repetition of this process provides (Z)-3 that is 98% isomerically pure. 

The naphthyl derived ligand, (5)-1-mcthyl-2-[(l-naphthylamino)methyl]pyrrolidine (4) is especially effective in the stereoselective additions of (Z)-l-cthylthio-l-trimethylsilyloxy-l-propene to aldehydes. Thus, quantitative formation of. yyn-adducts is achieved, in addition to high reagent-induced stereoselectivity (>98% ee for the 3-hydroxy thioester products)23 32. 

The barium hydroxide catalyzed Henry reaction of 6-deoxy-3-0-methyl-6-nilro-L-ta/r -pyra-nosc (17), generated from l,2-0-isopropylidcnc-3-0-mcthyl-o -D-r/7to-pcntodialdo-1.4-furanose (16), furnishes 5-deoxy-2-GMnethyl-5-nitro-wi o-inositol (18) in 92% yield and 90% purity1 2 3 4 5 6. 

The Ugi reaction has been successfully applied to the synthesis of oligopeptide derivatives, c.g.. in the construction of a pure tetra-L-valine derivative69. The 2-methylpropanaldimine 2 of (/7)-l-ferroccnyl-2-rnethylpropylarnine with /V-formyl-L-2-amino-3-methylbulanoic acid (3) as the carboxylic acid component and methyl A/-[(.S)-2-isocyano-3-mcthyl-l -nxo-buLyl -L-2-aiuino-3-inethylbutanoate (4) furnishes the diastereomeric valyl-valyl-valyl-valine derivatives in a ratio (S,S[R],S,S)i(S,R[R],S,S) of 91 9. The stereoselectivity of the process can be enhanced to 98.5 1.5 when two equivalents of tetraethylammonium A -formylvalinate are added. 

For reactions with S, specificity is found to decrease in the series cyanoisopropyl mcthyl Fbutoxy>phcnyl>bcnzoyloxy. Cyanoisopropyl (Scheme 3.3),7 f-bntoxy and methyl radicals give exclusively tail addition. Phenyl radicals afford tail addition and ca l% aromatic substitution. Benzoyloxy radicals give tail addition, head addition, and aromatic substitution (Scheme 3.4). ... 

Methyl hydrogen sebecate, 41, 34 Kolbe electrolysis of, 41, 33 1-Methylindole,40, 68 Methyl iodide, methylation of dihydroresorcinol with, 41, 57 Methyl isocyanide, 41, 15 Methyl 4-mcthyl-4-nitrovalerate, hydrolysis to acid, 41, 24 N-Methyl-N-nitrosoterephthalamide, preparation of diazomethane from, 41, 16... 

Pyran, tetrahydro-, 3 chloro 2 methyl [2H Pyran, tetrahydro, 3 chloro-2-mcthyl ], cis, trans mixture, 55, 64 2-PYRAZOLIN-5-ONES, 3-alkyl-, 55, 73 2-Pyrazolin 5-one, 3-(l-propyl)-, 55, 73 Pyridine, 2-amino-, p-bromination of, 55, 23... 

Interessante Trimere liefert 2-Mcthyl-propanal. Bei der Beschickung der beiden Elek-trodenraume einer geteilten Zelle (Platin-Elektroden) mit 2-Methyl-propanal/Tetra-butylammonium-hexafluorophosphat entsteht an der Anode 2,4,6-Triisopropyl-1,3,5-trioxan (95% d. Th.) und an der Kathode 4-Hydroxy-5,5-dimethyl-2,6-diisopropyl-l,3-dioxan (90% d. Th.), jeweils in sehr hoher Ausbeute1 ... 

Oxo-2-methyl- 273, 605 2-Oxo-3-methyl-l-(4-brom-phenyl)- 675 2-Oxo-3-methyl-1 -(3-chlor-phenyl)- 675 2-Oxo-3-methyl-l-(4-mcthyl-phenyl)- 675 l-Oxo-2-methyl-l -phenyl- 635... 

Der. 101 Cyclohexyl- 101 4-Methyl-phenyl- 101 2-Mcthyl-propyl- 101 Phenyl- 101, 124... 

Amino-2-methyl-1,1 -dideutero- 111 2-Amino-i-(3,4-methylendioxy-phenyl)- 80 1 -Amino-2 -(2 -mcthyl-propyloxy)- 472 2-Amino-l-oxo-l-phenyl- 325 1 -Amino-1 -phenyl -... 

Methyl-1-athyliden- 402 2-Mcthyl-l,l-diphenyl- 391 2-Mcthyl-l-heptyl- 676 Methyl-hydroxymethyl-... 

Oxo-2-thiono-5-(3-carboxy-propyl)-1-phenyl- 252 4-Oxo-2-thiono-l,5-dimethyl- 252 4-Oxo-2-thiono-5,5-diphenyl- 252 4-Oxo-2-thiono-l-mcthyl-5-phenyl- 252 4-Oxo-2-thiono-5 -methyl-1 -phenyl- 252 4-Oxo-2-thiono-4-(2-methyl-propyl)- 252 4-Oxo-2-thiono-l-phenyl- 252 2-Thiono-5,5-diphenyl- 252... 

Methyl- -1,2-dicarbonsaure-anhydrid 176/. (Z)-l-Mcthyl-2-(2-hydroxy-athyl)-1 -methoxycar-bonyl-... 

Methoxy-4-methyl-2 -phenyl- 595 4-Mcthoxy-2 -phenyl- 595 4-Mcthyl-2-phenyl- 595... 

Methyl-3-acetyl- -1-oxid 693 l-Mcthyl-4-cyan-l,4-dihydro- 593 Methyl-dihydro- 592... 

Bis-[athyl-cydopcntadienyl-eisen)-methyl- 589 Bis-[cyclopentadienyl-eisen]-mcthyl- 589... 

CN [6/ -[6ct.7p(Z)]]-7-[[(2-amino-4-thiazolyl)(methoxyimino)acetyI]aniino]-8-oxo-3-[[(l,2,5,6-tetrah)/dro-2-mcthyl-5,6-dioxo-l,2,4-triazin-3-yl)thio]methyl]-5-thia-l-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid... 

CN 3-[(4-amino-2-methyl-5-pyrimidinyl)mcthyl]-5-(2-hydroxyethyl)-4-methylthiazolium chloride monohydrochloride... 

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