Electron impact mass spectrometry of nuphar alkaloids. II—Thiohemiaminals

Abstract

The appearance of m/e 228 and 176 ions, useful in ascertaining the presence of the hemiaminal hydroxyl, are discussed for six thiaspirane-type herniaminals isolated from Nuphar luteurn and three epimeric pairs of a-thiohemiaminals derived from (-)-deoxynupharidine. Other groups of ions useful in ascertaining stereochemical differences of the sulfur moiety in a-thiohemiaminals are discussed for the same compounds. One such group of ions is comprised of 248, 246 and 231; a second is 192 and 191.

Indolizidines, .alpha.-arylthiohemiaminals, and .alpha.-arylsulfonylhemiaminals from a quinolizidine enamine and an arenesulfonyl chloride

“…Caled for C22H29NO3S: C, 68.18; H, 7.54; N, 3.62. Found: C, 68.33; H, 7.59; N, 3.50. 7a-(p-Toluenesulfonyl)-7-epideoxynupharidine (13). A solution of 32 mg of 7a-(p-toluenesulfonyl)-7-epideoxynupharidin-6-ol (7) in MeOH was treated with one portion of 39 mg of NaBH* at 25 °C for 12 h. The solution was concentrated and thereafter chromatographed on 10 g of A1203 (activity II) which was eluted with 50 ml of CeHe, 40 ml of 3:1 CgHg-EtgO, 50 ml of 3:2 CeHg-EtgO, and 30 ml of Et20.…”

“…Transformation of 7ce-(p-Tolylthio)deoxynupharidine (11) to 7a-(p-Toluenesulfonyl)deoxynupharidine (13). A solution of 3.6 mg of 11 in 0.45 ml of acetic acid was treated with 0.05 ml of 30% H202 at 25 °C for 25 h. The solvent was removed at reduced pressure and the residue basified with a drop of pyridine.…”

Mass spectrometry of sulfur‐containing compounds in organic and bioorganic fields

“…The mass spectrometry of these C,,-derivatives has been studied in detail (169)(170), and ions at ml'z 178 and 230 have shown to be characteristic and related to the fragmentation of the tetrahydrothiophene and quinolizidine rings, Scheme 31. On the other hand, the mass spectra of hemiaminals (160, [171][172] are characterized by the presence of mlz 176 and 228 ions. The formation of the former is shown in Fig.…”

Synthesis of α-thiohemiaminal derivatives of deoxynupharidine

“…The ir indicated the presence of the 3-fury1 and 1,4-disubstituted aryl groups respectively in the appearance of 11.5 and 12 1l.m absorption bands. The mass spectra revealed mle 248, 231, 192, 176, 107, and 94, peaks characteristic of a C-6 hemiaminal incorporated in a deoxynupharidine skeleton (13).…”