Pyrrolizinium, 1,2,3,5,6,7-hexahydro-, perchlorate → 7a-ethynylhexahydro-1H-pyrrolizine

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Reaction Steps

The compound from step 15a above (1.0 g, 4.8 mmol) was added to a solution of 0.5 M ethynylmagnesium bromide (29 mL, 14.3 mmol) in THF at room temperature. The reaction mixture was stirred for 45 minutes, quenched with 15% NaOH solution, and diluted with brine:water (1:1). The aqueous phase was extracted with CH2Cl2, and the organic phases were combined, dried (MgSO4), concentrated and chromatographed (silica gel; CHCl3 /MeOH, 90:10) to afford an amber oil (463 mg, 71%): 1H NMR (CDCl3, 300 MHz) δ 1.75-2.06 (m, 6H), 2.14-2.23 (m, 2H), 2.33 (s, 1H), 2.53-2.62 (m, 2H), 322-3.28 (m, 2H); MS (CI/NH3) m/z: 136 (M+H)+.

Provenance & Evidence