Original scientific paper

Preparation and Properties of Some Pro chiral and Chiral Precursors of S-3-(3-Hydroxyphenyl)-1-propylpiperidine (S-3-PPP)

Zlata Raza ; »Ruđer Bošković« Institute, P.O.B. 1016, 41000 Zagreb, Croatia, Yugoslavia
Senka Đaković ; »Ruđer Bošković« Institute, P.O.B. 1016, 41000 Zagreb, Croatia, Yugoslavia
Ivan Habuš ; »Ruđer Bošković« Institute, P.O.B. 1016, 41000 Zagreb, Croatia, Yugoslavia
Vitomir Šunjić ; »Ruđer Bošković« Institute, P.O.B. 1016, 41000 Zagreb, Croatia, Yugoslavia

Abstract

Various synthetic approaches to 2,3-dehydro- and 3,4-dehydro-1-propio- nylpiperidines 12,13 and to their 1-propyl congeners 14,15,-two pairs of unsaturated, regioisomeric precursor of S-(-)-3-PPP [S-(-)-3-(3-hydroxyphe- nyl)-l-propylpyperidine, 20] were investigated. Compounds 12 and 13 were prepared by regioselective elimination of water in 11. Preparation of 14 and 15 by two different methods is described. The ratio of the E/Z isomers at the C(0)-N bond in 11-13 was determined by 13C-NMR, and separation of the enantiotopic XH-NMR signals in the enantiomers of 18 and 19 was investigated with chiral shift reagent Eu(tfc>3. Hydrogenation of 15 was performed with five different Rh(l) catalytic complexes, affording the O-methyl-conge- ner of 3-PPP 19. Complete conversion of 15 into 19 was only achieved at elevated temperature and/or pressure to give the R- or S-isomer with low enantioselectivity (7-18% e.e.).

Keywords

Hrčak ID:

137373

URI

https://hrcak.srce.hr/137373

Publication date:

30.6.1991.

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