Asymmetric Synthesis of Ring Functionalizedtrans-2,6-Disubstituted Piperidines fromN-Sulfinyl δ-Amino β-Keto Phosphonates. Total Synthesis of (−)-Myrtine

Abstract

Sulfinimine-derived N-sulfinyl δ-amino β-ketophosphonates are transformed via the enaminone to the phosphoryl dihydropyridones that selectively give trans-2,6-disubstituted 1,2,5,6-tetrahydropyridines on organocuprate addition and dephosphorylation.

Addition of Organometallic Reagents to Chiral N‐Methoxylactams: Enantioselective Syntheses of Pyrrolidines and Piperidines

“…In all cases, cis isomers were obtained with excellent diastereoselectivity (more than 10:1). The configurational assignment was based on comparison with literature [26] 27, [33] 29, [33a] and 31 [34] ); the axial disposition of both 2-H and 6-H was apparent from vicinal coupling constants (J = 10.4-10.8 and 2.2-2.5 Hz) for all products. For a few selected examples the cis-configuration was further verified by NOESY experiments (see the Supporting Information).…”

A convenient allylsilane-N-acyliminium route toward indolizidine and quinolizidine alkaloids

“…(+)-Myrtine and (-)-epimyrtine are quinolizidine alkaloids isolated from Vaccinium myrtillus (Ericaceae). [ 4 , 5 ] Several syntheses of these compounds as racemic mixtures have been described, [ 42 - 45 ] but only three enantioselective syntheses of (+)-myrtine [ 46 , 47 ] and three syntheses of (-)-epimyrtine have been published. [ 48 , 49 ]…”

Efficient synthesis of β’-amino-α,β-unsaturated ketones

“…The relative stereochemistry of piperidine 2a was confirmed by further transformation to the known compound 3 [16–17] with 94% ee. In order to establish this new approach as a general method for the preparation of chiral 2,6-disubstituted piperidines, we wish to report here a facile synthetic route to various β’-carbamate-α,β-unsaturated ketones in good overall yields and good enantioselectivities.…”