Photochemical rearrangements,

BUTENE. As shown in Figure 38, a group attached to C-1 can migrate from position 1 to 3 (1,3 shift) to produce an isomer. If it is a methyl group, we recover a 1-butene. If it is a hydrogen atom, 2-butene is obtained. A third possible product is the cyclopropane derivative. The photochemical rearrangement of 1-butene was studied extensively both experimentally [88]... 

The main features are the molecular ions as the base peak and the M-t-1 ions arising from another species. For 2-aminothiazole the m/e 73 ion (M-HCN) is shifted to m/e 75 in the spectrum of the dideuteroamino derivative and, therefore, largely arises via rupture of 2-3 and 4-5 bonds (Scheme 18). This fragmentation process could involve the kind of intermediates postulated in photochemical rearrangements (see Chapter III, Section IX.3.B). The other fragments fit well the general pattern of fragmentation proposed by Clarke (136). 

The photochemical rearrangement of the mesolonic thiazole (33) provides an original synthesis of the 4-methylthio-derivatives of the A-4-thia2oline-2-one (34) (Scheme 15) (33). 

Cyanopyrrole undergoes photochemical rearrangement to 3-cyanopyrrole. If the analogous rearrangement of IV-methyl-2-cyanopyrrole (22) is carried out in methanol, in addition to the 3-cyanopyrrole (24) the bicyclic intermediate (23) is trapped as the methanol adduct (25) (78CC131). 

Azocin-2( 1H )-one, hexahydro- 1-phenyl-photochemical rearrangement, 7, 656 Azodn-2( 1H )-one, 1,2,7,8-tetrahydro-synthesis, 7, 662 Azocin-5-one IR spectra, 7, 16 transannular interactions, 7, 14 Azocin-5-one, l-(2,4-dimethylphenyl)-IR spectrum, 7, 657 Azocin-5-one, methoxycarbonyl-synthesis, 7, 657 Azocin-5-one, 1-methyl-IR spectrum, 7, 657 synthesis, 7, 657 Azodn-5-one, 1-p-tolyl-IR spectrum, 7, 657 Azocinones... 

H-Benzo[a]carbazole, 4,4a,5,l 1,1 la,l Ib-hexahydro-synthesis, 4, 283 Benzo[b]carbazole, N-acetyl-photochemical rearrangements, 4, 204 Benzo[/]chroman-4-one, 9-hydroxy-2,2-dimethyl-synthesis, 3, 851 Benzochromanones synthesis, 3, 850, 851, 855 Benzochromones synthesis, 3, 821 Benzocinnoline-N-imide ring expansion, 7, 255 Benzocinnolines synthesis, 2, 69, 75 UV, 2, 127 Benzocoumarins synthesis, 3, 810 Benzo[15]crown-5 potassium complex crystal stmcture, 7, 735 sodium complex crystal stmcture, 7, 735 Benzo[ 18]cr own-6 membrane transport and, 7, 756 Benzo[b]cyclohepta[d]furans synthesis, 4, 106 Benzocycloheptathi azoles synthesis, 5, 120... 

Imidazole, 2,4,5-trichloro-1-methyl-chlorination, 5, 398 Imidazole, 2,4,5-trideutero-iodination, 5, 401 Imidazole, 1-trifiuoroacetyl-reactions, 5, 451-452 Imidazole, 2-trifiuoromethyl-hydrolysis, 5, 432 Imidazole, 2,4,5-triiodo-nitration, 5, 396 synthesis, 5, 400 Imidazole, 1,2,4-trimethyl-photolysis, 5, 377 rearrangement, 5, 378 Imidazole, 1,2,5-trimethyl-photochemical rearrangement, 5, 377 rearrangement, 5, 378 Imidazole, 1,4,5-trimethyl-bromination, 5, 399 3-oxide... 

Isoxazolo[5,4-h]pyridine applications, 6, 634 photochemical rearrangement, 6, 662 synthesis... 

Oxazol-4(5ff)-one, 5-acetyl-5-methyl-synthesis, 6, 225 Oxazol-4(5ff)-one, 2-phenyl-photorearrangement, 6, 200 synthesis, 6, 225 Oxazol-5(2ff)-one, 2-acyl-2,4-disubstituted pyrolysis, 6, 200 Oxazol-5(2H)-one, allyl-photochemical rearrangement, 6, 200 Oxazol-5(2ff)-one, 2-arylmethylene-synthesis, 6, 227... 

Pyrrole, 2-cyano-l-(2-hydroxyethyl)-5-nitro-ipso substitution, 4, 243 Pyrrole, 2-cyano-l-methyl-photochemical rearrangement, 4, 42 photolysis, 4, 203 Pyrrole, 2-cyano-3-methyl-photochemical rearrangement, 4, 202 Pyrrole, 2-cyano-4-methyl-photochemical rearrangement, 4, 202 Pyrrole, 2-cyano-5-methyl-photochemical rearrangement, 4, 202 Pyrrole, diacetoxymethyl-synthesis, 4, 274 Pyrrole, 2,4-diacetyl-synthesis, 4, 218 Pyrrole, 2,5-diacetyl-synthesis, 4, 218, 219 Pyrrole, 2,4-dialkyl-... 

Thiophene, 3-pentadeuterophenyl-chemical shifts, 4, 730 Thiophene, 2-phenyl-oxidation, 4, 800 phototranspositions, 4, 743 rearrangement, 4, 42 reduction, 4, 775 synthesis, 4, 865, 914 UV spectrum, 4, 735 Thiophene, 3-phenyl-photochemical rearrangements, 4, 735 phototranspositions, 4, 743 lsmeier formylation, 4, 759 Thiophene, 2-pivaloyl-Birch reduction, 4, 775 Thiophene, polybromo-reactivity, 4, 829 Thiophene, polylithio-synthesis, 4, 831 Thiophene, (propargylthio)-rearrangement, 4, 746 Thiophene, 2-(3-pyridinyl)-synthesis, 4, 781 Thiophene, 2-(5-pyrimidinyl)-synthesis, 4, 781 Thiophene, 3-pyrrolidinyl-cycloaddition reactions, 4, 68 with dimethyl acetylenedicarboxylate, 4, 788-789... 

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