Addition of thiiranes to ?1-piperideines and ?1-pyrrolines

Synthesis of tryptamines by the Fischer method using synthetic precursors and latent forms of amino-butanal (review)

“…Similar behavior has been recorded for dimethylpyrroline 27c [37]. Recent investigation of the equilibria existing in an aqueous solution of the pyrroline 28 showed that the trimer 3 predominates in an alkaline medium with the monomer 28 as impurity.…”

“…The reductive cyclization of the acetals of substituted nitrobutanals 26a,b [158] and the diethyl acetal of 4-cyano-3,3-dimethylpropanal [37] leads to the production of the pyrrolines 27a,b and 27c (R 1 = R 2 = H,…”

“…The latent forms of aminobutyraldehyde, found in plants, participate in the biosynthesis of alkaloids [31][32][33]. 4-Chlorobutanal (1) [31], the acetals of 4-aminobutanal 2 [32,34,35], and their equivalent trimers 1-pyrrolines 3 [33,36,37] are therefore used widely for the synthesis of alkaloids. 1-Acylpyrrolines [36,38] and also 2-alkoxy- [39][40][41] and 1-acyl-2-hydroxypyrrolidines [42] have found widespread use in the synthesis of alkaloids and various other nitrogen heterocycles.…”

Stereochemistry and nmr Spectra of Some Tricyclic Condensed Thiazolidine Derivatives with a Bridgehead Nitrogen Atom

“…The mechanism of the reaction involves opening of the thiirane ring by an imine or α-ethoxyamine (if ethanol is present in the reaction mixture) and is accompanied by inversion of the configuration of the attacked carbon atom of the thiirane [2]. This method of synthesis of thiazolidines is particularly effective in the case of cyclic imines in that it opens up the simple possibility for synthesis of bicyclic condensed derivatives with a nitrogen atom at the bridgehead position or their analogs with a larger number of rings [1,3,4].…”

“…High diastereoselectivity is indeed often observed for cyclic imines, and in many cases the de value approximates to 100%. However, determination of the configuration of the main or sole diastereomer represents a difficult task [3,5], which in a number of cases has not been possible to solve [1].…”