1: MsCl, DMAP 3: 97 percent / PPTS / methanol 4: CrO3, H2SO4 5: L-selectride 6: 75 percent / Na, liq. NH3 View Scheme

<b>Multi-step reaction with 12 steps<br /> </b>2: acid hydrolysis<br />3: Pb(OAc)4<br />4: over Li-acetylide<br />5: 49 percent / Swern oxidation<br />6: Zn(BH₄)2 / diethyl ether<br />7: LiAlH₄ <br />9: acid, H₂O<br />10: NH₂OH*HCl, pyridine<br />11: 5percent sodium hypochlorite, Et₃N<br />12: H₂, boric acid / W-2 Raney nickel<br /> <br /> &nbsp;

<b>Multi-step reaction with 10 steps<br /> </b>1: Pb(OAc)4<br />2: over Li-acetylide<br />3: 49 percent / Swern oxidation<br />4: Zn(BH₄)2 / diethyl ether<br />5: LiAlH₄ <br />7: acid, H₂O<br />8: NH₂OH*HCl, pyridine<br />9: 5percent sodium hypochlorite, Et₃N<br />10: H₂, boric acid / W-2 Raney nickel<br /> <br /> &nbsp;

<b>Multi-step reaction with 11 steps<br /> </b>1: acid hydrolysis<br />2: Pb(OAc)4<br />3: over Li-acetylide<br />4: 49 percent / Swern oxidation<br />5: Zn(BH₄)2 / diethyl ether<br />6: LiAlH₄ <br />8: acid, H₂O<br />9: NH₂OH*HCl, pyridine<br />10: 5percent sodium hypochlorite, Et₃N<br />11: H₂, boric acid / W-2 Raney nickel<br /> <br /> &nbsp;