The synthetic method is simple and convenient and direct; and the spiralring skeleton obtained from spiro-diketone has optical pure chiral ligand with different absolute configurations.
I stopped to look at Mosh Shternberg’s silver work and bought a spiral-shaped ring that wraps around my ring finger, for the equivalent then of about $37.
我在摩西 希腾堡银器店停下脚步,买了一只螺旋状的戒指戴在无名指上,这只戒指的价值相当于37美元。
3
A screwdriver is used to remove the spiral seat retainer ring from its groove.