ISSN:
0947-3440
Keywords:
Polar additions
;
Alkynes
;
Transannular interactions
;
Neighboring group effects
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The reactions of 1,6-dialkyl-1,6-diazacyclodeca-3,8-diynes (9, a = CH3, b = C2H5, c = i-C3H7) with HCl, H2O and CH3OH have been investigated. The reaction of 9c with HCl selectively gives N,N′-diisopropyl-4-chloro-1,2,3,5,6,7-hexahydro-2,6-naphthyridine (13c) in quantitative yield. Investigation of this reaction at different temperatures allows the activation parameters for the process to be derived (ΔH≠ = 24 ± 1 kcal · mol-1, ΔS≠ = - 9 ± 2 cal · mol-1 · K-1). The regioselective reaction of 9c with methanol affords a quantitative yield of N,N′-diisopropyl-4-methoxy-1,2,3,4,5,6,7-hexahydro-2,6-naphthyridine (29c). Addition of water to 9a in the presence of H2SO4 gives N,N-dimethyl-7-oxo-1,2,3,4,5,6,7,8-octahydro-2,6-naphthyridine (28a) in low yields (15%). If the addition of water is carried out in the presence of Hg2+, the yield of 28a is increased considerably. The mechanisms of all three reactions are discussed and those involving electrophilic addition (AdE2) are favored.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199719970620
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