Acetone pyrrole alkylation

The precedent is strong for the Involvement of oxetanes as Intermediates in carbonyl additions to pyrroles.5 7 NMR evidence has been obtained for an oxetane adduct of acetone and N-methylpyrrole.4 The initial photoadduct was shown to rearrange readily on workup to the 3-(hydroxy alkyl) pyrrole derivative. 

The first documented synthetic macrocycle was synthesized by Baeyer via the condensation of pyrrole and acetone in the presence of mineral acid (Baeyer, 1886). Other examples, from a historical point of view, are listed in a review by Newkome and coworkers (Newkome et al., 1977). The aliphatic macrocycles were synthesized later as exemplified by Willstatter s synthesis of eight-membered rings (Willstatter and Veraguth, 1905) and Ruzicka s studies of the chemistry of muscone and civetone (Ruzicka, 1926). The synthesis of thiacycloalkanes using the reaction of sodium sulfide with an alkyl dihalide was also investigated early in the twentieth century (Braun and Tcherniac, 1907). A cyclam (cyclic amine) was first synthesized by Alphen (1937). The preparation of the peraza-crowns was first developed by Stetter (1953a,... 

The reaction of pyrroles with two free a-positions with aldehydes occurs between four molecules of aldehyde and four pyrroles and leads to cyclic condensation products (which is the basis of a simple porphyrin synthesis, cf p. 553). Acetone reacts in a similar manner with four pyrrole units to give a cycHc tetramer 24 directly in high yield by a hydroxyalkylation/alkylation sequence [105] ... 

New calix[4]pyrroles 145 bearing dipyrrolylquinoxaline as strapping elements have been synthesized (Kim et al. 2009). The synthesis of receptor 145 starts with ketone 142, a species that was prepared by the reaction of oxalyl chloride with 2 equivalents of 2-(3-oxobutyl)pyrrole (Yadav et al. 2001). Once in hand, 142 was reacted with 4-nitro-1,2-DAB in the presence of acid to afford bisketone 143 in 24 % yield (Black et al. 1999 Anzenbacher et al. 2000). Treatment of this latter intermediate with neat pyrrole in the presence of trilluoroacelic acid afforded the bis-dipyrromethane 144 in 74 % yield (Scheme 5.34). While this procedure proved effective, attempts to effect the direct alkylation of 6-nitro-2,3-di(2 -pyrrolyl)qui-noxaline with methyl vinyl ketone produced only trace quantities of the desired product 144. Acid-catalyzed condensation of 144 with acetone then gave the... 

Rahm et al. describes the formylation of anisole (50% isolated yield) and alkylated benzenes in fair yield using acetone cyanohydrin (Eq 1.19). Similar to the Gattermann reaction no formylation is obtained with pyrrole and only traces of aldehydes were observed with phenol and furane as substrates. 

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