Novel route to the synthesis of hydroxylated piperidine and pyrrolidine derivatives via the intramolecular reaction of γ-aminoallylstannane with aldehyde

Stereoselective Synthesis of Piperidines

“…A nice example for the former reaction type, which was described by Yamamoto, is the intramolecular addition of an allyltributylstannane moiety to the aldehyde in 254 yielding 3-hydroxy-2-vinylpiperidines 255, 256 (Scheme 61). 156 The diastereoselectivities were highly dependent on the cyclization conditions. In the presence of BF 3 •OEt 2 the trans-configurated piperidine 255 was obtained as the major product (d.r.…”

Stereoselective Introduction of Hydroxyl Group to Piperidine Ring using Electrochemical Method

“…1) Also, there have been a variety of natural products possessing a hydroxylated piperidine moiety. 2) So, it is very much worthwhile to exploit new methods for stereoselective introduction of hydroxyl group to a piperidine ring. In this paper, we will present a facile method using electrochemical oxidation for stereoselective introduction of a hydroxyl group to the β-position of a piperidine ring.…”

Synthesis of Racemic Brevioxime and Related Model Compounds

“…This approach which, in the event, proved successful was initially tried with model compounds. We prepared first of all 14 (see Scheme 2) from the two components 10 and 11 . Both of these are known compounds, and they were obtained by the literature methods.…”

“…Ethyl acetoacetate was methylated via its pyrrolidine enamine and hydrolyzed under carefully controlled conditions, to afford the sensitive acid 11 . 4-Aminobutanol was best prepared in three steps from tetrahydrofuran (AcCl, heat, 66%; phthalimide, DMF, NaI, heat, 88%; aqueous KOH, heat, 64%), and silylation then gave the protected amine 10 . Coupling of 10 and 11 was achieved using DCC (62−92%), and then desilylation (Bu 4 NF) gave alcohol 13 .…”

“…4-Aminobutanol was best prepared in three steps from tetrahydrofuran 13 (AcCl, heat, 66%; phthalimide, DMF, NaI, heat, 88%; aqueous KOH, heat, 64%), and silylation then gave the protected amine 10. 10 Coupling of 10 and 11 was achieved using DCC (62-92%), and then desilylation (Bu 4 NF) gave alcohol 13. From that point, oxidation with Pr 4 NRuO 4 -N-methylmorpholine N-oxide 14 led directly to the simple model compound 14 (33%).…”