2H-Pyrroles, 3,4-dihydro-

H-Pyrrole, 3,4-dihydro-5-methyl-UV, 4, 179 (65JCS2313) lH-Pyrrole-3-acetic acid, ester C NMR, 4, 172 (74JCS(P2)1004)... 

Phenyl-1-pyrroline 1-Pyrroline, 2-phenyl- (8) 2H-Pyrrole, 3,4-dihydro-5-phenyl-(9) (700-91-4)... 

Propionic acid, 2-iodo-3-nitro-, ethyl ester [Propanoic acid, 2-iodo-3-mtro-, ethyl ester], 65 2//-Pyran, 3,4-dihydro-, 51 2//-PYR AN-2-ONE, 49 2H Pyran 2-one, 5 bromo 5,6-dihydro, 50 27/-PYRAN-2-ONE, 5,6 DIHYDRO-, 49 PYRIDINE, 2,3,4,5 TETRAHYDRO, 118 Pyridines, -substituted, 34 a Pyrone-6-carboxyhc acid [2H Pyran-6-Larboxyhc acid 2-oxo ], 51 Pyrroles, 34... 

Ethoxypyrrolin-5-one l-Pyrrolin-5-one, 2-ethoxy- (8) 2H-Pyrrol-2-one, 5-ethoxy-3,4-dihydro- (9) (29473-56-1) tert-Butyl N-(l-ethoxycyclopropyl)carbamate Cyclopropanecar-bamic acid, 1-ethoxy-, tert-butyl ester (8) Carbamic acid, (1-ethoxycyclopropyl)-, 1,1-dimethylethyl ester (9) (28750-48-3 41879-49-6)... 

DEPMPO 2-Diethoxyphosphoryl-2-methyl-3,4-dihydro-2H-pyrrole-l-oxide... 

It is interesting to note that these compounds attract mainly the males of the respective species. Therefore, these compounds might be pheromone mimics. Protein hydrolysates, on the other hand, attract both sexes of most Tephritids and are widely used as food baits. However, volatiles from protein hydrolysates may not be simply food attractants. The cyclic imine, 3,4-dihydro-2H-pyrrole, has been identified in protein hydrolysate volatiles (12), and this compound has been identified by Baker and coworkers (11) as the sex pheromone Which attracts virgin females to the sexually mature male Medflies. Why the protein hydrolysate volatiles attract the males and other species remains unanswered. 

In 2006, Chatani and coworkers published a rhodium vinylidene-mediated alkyne cyclodimerization incorporating allylamine (Table 9.13) [26]. Although RhCl(PPh3)3 alone was a competent catalyst for the stereospecific formation of ( )-3-alkylidene-3,4-dihydro-2H-pyrroles (69), the addition of an ammonium salt helped to suppress undesired alkyne homocoupling. Under optimized conditions, a variety of functionalized alkynes underwent cyclodimerization with allyl- or crotylamine in good yield. 

Photochemical transformations of y,5-unsaturated oximes ethers (59) to 3,4-dihydro-2H-pyrrole derivatives (60) have been developed by Mikami and Narasaka [50]. Irradiations were performed in the presence of 1,5-dimethoxynaphthalene (DMN) as sensitizer and 1,4-cyclohexadiene as hydrogen source. Mono- and bicyclic products were obtained selectively by 5-exo cyclization in moderate to good yields (Sch. 29). 

Generation of the iminyl radical 184 in the above experiment was confirmed by an intramolecular radical trapping experiment. Reaction of l-phenylhept-6-en-3-one 0-2,4-dinitrophenyloxime (87) with m-cresol and NaH afforded 2-methyl-5-(l-phenylethyl)-3,4-dihydro-2H-pyrrole (88), which is the addition product of iminyl radical 187, obtained in 27% yield (Scheme 40). 

H-Pyrrol 3 -Methoxycarbonyl-5-phenyl-3,4-dihydro- E14b, 22 (Azirin 4- En)... 

Since, the original presentation of this paper, the pheromone of the Mediterranean fruit fly has been identified (23). The compounds, 3,4-dihydro-2H-pyrrole, ethyl-E-3-octenoate, E,E,-0(-farnesene, and geranyl acetate, bear no obvious resemblance to the active components of trimedlure. The origin of the biological activity of the synthetic, therefore, remains enigmatic. 

Das aus Pyrrolidin durch N-Chloricrung und anschlieBende Chlorwasserstoff-Abspal-tung mit Basen zugangliche 3,4-Dihydro-2H-pyrrol addiert in Analogie zur Strecker-Reak-tion mit Iminen (s. S. 535) Cyanwasserstoff zum 2-Cyan-pyrrolidin. Durch saure Hydrolyse wird dl-Prolin erhalten (Gesamtausbeute 45%)7 ... 

C.G. Overberger, K.-H. Davidu. J.A. Moore, Macromolecules5, 368 (1972) die untersuchte Verbindung, 2-Carboxy-5-methyl-3,4-dihydro-2H-pyrrol, wurde auf einem anderen Weg hergestellt. 

---