Lactams ketones, cyclic

Irradiation of iV-phenyl lactams affords cyclic products selectively rearranged to the ortho position. Studies on the influence of the chain legth on the regioselectivity of the PFR of several lactams have found that, even with 11 methylenes between the nitrogen atom and the carbonyl group, the coupling product was always the ortho ketone (Scheme 36) [95,96]. 

If other active groups are y or 8 to the nitro group, hydrogenation can result in the formation of cyclic products. Esters condense with the product amine to give lactams. Ketones or aldehydes produce imines that can be hydrogenated further to an amine. The hydrogenation of y- or 5-nitro carboxylic acids under mild conditions, however, gives the amino acids in excellent yields.58.59 The... 

KETONE, CONJUGATE ALLYLATION OF a,g-UNSATURATEO. 62, 86 KETONE, a-TERT-AUYLATION, 62. 95 Ketones, a,6-acetylen1c, asymnetrlc reduction, 63, 63 Ketones, cyclic, lactams from, 63, 188 Ketones, e-hydroxy-, synthesis of, 63, 79... 

P-Ketoamides and simple ketones can also be used as nucleophiles in the corresponding intramolecular additions, which afforded lactams and cyclic ketones, respectively, with good yields and /ran -selectivity. Highly active cationic gold(I) catalysts formed in situ from Au[P(t-Bu)2(o-biphenyl)]Cl or IPrAuCl and silver salts were used for these transformations (Scheme 4-16). 

Lactams from cyclic amines. A mixture of iodosobenzene and water stirred for 15 min, the slurry cooled to 0°, treated in one portion with pyrrolidine, stirred at 9" for 1 h, then at room temp, until a clear soln. was obtained (4-5 h) - 2-pyrrolidinone. Y 49%. F.e. inch 3,4-dihydroisocarbostyrils and 2-piperidones, also nitriles from prim, amines, and cyclic ketones from cycloalkylamines, s. R.M. Moriarty et al., Tetrahedron Letters 29, 6913-6 (1988) cyclic azomethines in methylene chloride cf. ibid. 6917-20. 

Schiff bases s. Azomethines Schlotterbeck s. Buchner Schmidt reaction 17, 524 —, amines from carboxylic acids 19, 305 20, 366 —, lactams from ketones, cyclic, ring expansion... 

Poly phosphoric acid sodium azide Lactams from cyclic ketones by Schmidt reaction and from cyclic oximes by Beckmann rearrangement Ring expansion... 

CO) aromatic O, quinones, lactones, lactams, unsaturated cyclic ketones, allyl aldehydes... 

Mesitylenesulfony loxylamine/alumina Lactams from cyclic ketones Ring expansion s. 32,285... 

Lactams from cyclic ketones—Electrostatic effects on the Schmidt reaction s. 13, 379 bicyclic lactams s. R. J. Michaels and H. E. Zaugg, J. Org. Ghem. 25, 637 (1960)... 

Poly phosphoric acidinitromethane Lactams from cyclic ketones... 

The first /3 -lactam was produced by addition of a ketene to an imine and there are now many examples of this type of approach. The ketenes are most frequently generated in situ from acid chlorides by dehydrohalogenation, but have also been produced from diazo ketones, by heating of alkoxyacetylenes and in the case of certain cyanoketenes by thermolysis of the cyclic precursors (162) and (163). 

Cyclic enamines with an isomeric position of the double bond have been obtained by the addition of Grignard reagents to five- (78-81), six- (82-86), seven- (87-90), and thirteen- (89-91) membered lactams, whereas other medium-sized (92,93) lactams furnished amino ketones. The reaction has been extended to substituted lactams (94-98), and iminoethers (99,100). 

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