94. “Aminocyclopentitols from N-Alkylpyridinium Salts: A photochemical approach”
    Acar, E. A.; Glarner, F.; Burger, U.
    Helv. Chim. Acta 1998, 81, 1095-1114.

The photolysis of N-alkylpyridinium halides 9a–e in alkaline H₂O gave 6-azabicyclo[3.1.0]hexenol derivatives 10a–e. N–Substituents bearing ether, acetal, and alcohol functions were found to do not adversely influence the photochemical reaction course. The free OH groups of the N–(3-hydroxypropyl) derivative 10d were protected by benzoylation. The ensuing dibenzoate 14 underwent stereocontrolled opening of the aziridine ring on reaction with MeSH/BF₃ to give a thioether 15. With benzoic acid in CHCI₃, 10d gave the 4-hydroxy-5-aminocyclopent-2-enyl benzoate 11. The meso-2-aminocyclopent-4-ene-1,3-diol 12 was obtained by hydrolysis of 11. On reaction with Boc₂O and NaI, the aziridine ring of 14 was converted to a bicyclic compound 17. Hydrolysis of 17 provided the trans-1,3-diol 18, the epimer of 12. Face-selective dihydroxylation of Boc-protected 12 gave a meso-aminocyclopentanetetrol 23 which was characterized upon peracetylation. Dihydroxylation of 15 provided a racemic analogue of epi-mannostatin A (26).

DOI : 10.1002/hlca.19980810523 

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