1,4-Dioxaspiro[4.5]decan-8-one → 8-(6-Cyano-1,2,3,4-tetrahydroisoquinolin-2-yl)-1,4-dioxaspiro[4,5]decane

Participants

Reaction Steps

A solution of cyclohexane-1,4-dione monoethylene ketal(5.3 g, 33.9 mmole) and 6-cyano-1,2,3,4-tetrahydro-isoquinoline (5.3 g, 28.5 mmole) was treated with sodium cyanoborohydride (2.13 g, 33.8 mmole)at room temperature and stirred at ambient temperature for 18 hr. The reaction was concentrated to 1/4 volume at reduced pressure and poured into sat. NaHCO3 (500 ml ) and extracted with EtOAc (3×500 ml ). The combined organic layers were dried over anhydrous MgSO4 and evaporated under reduced pressure. The resulting foam was chromatographed on silica gel, eluting with 50% ethyl acetate/hexane to give 7.01 of product as a white solid which was recrystallized from ethanol. MP=127° C.

Provenance & Evidence