623571-19-7Relevant articles and documents
Synthesis of the spermidine alkaloids (-)-(2R,3R)- and (-)-(2R,3S)-3-hydroxycelacinnine: Macrocyclization with oxirane-ring opening and inversion via cyclic sulfamidates
Khanjin, Nikolai A.,Hesse, Manfred
, p. 2028 - 2057 (2007/10/03)
The two epimers (-)-1a and (-)-1b of the macrocyclic lactama kaloid 3-hydroxycelacinnine with the (2R,3R) and (2R,3S) absolute configurations, respectively, were synthesized by an alternative route involving macrocyclization with the regio- and stereoselective oxirane-ring opening by the terminal amino group (Schemes 2 and 6). Properly N-protected chiral trans-oxirane precursors provided (2R,3R)-macrocycles after a one-pot deprotection-macrocyclization step under moderate dilution (0.005-0.01M). The best yields (65-85%) were achieved with trifluoroacetyl protection. Macrocyclization of the corresponding cis-oxiranes was unsuccessful for steric reasons. Inversion at OH-C(3) via nucleophilic displacement of the cyclic sulfamidate derivative with NaNO2 led to (2R,3S)-macrocycles. The synthesized (-)-(2R,3S)-3-hydroxycelacinnine ((-)-1b) was identical to the natural alkaloid.