Reaction #215081

Reaction equation

ethyl acetate

lactic acid

p-toluenesulfonyl chloride

3-t-butoxycarbonylamino-2-hydroxymethyl-4-oxoazetidine

→

crystalline title product

Yield 71.6%

cis-3-t-Butoxycarbonylamino-4-oxo-2-azetidinylmethyl tosylate

Yield 71.6%

Solvents

pyridine

Conditions

Workup

1. 1
   workup.WAITstored at 5° overnight
2. 2
   workup.STIRRINGthe mixture is stirred for 1 hr
3. 3
   Washwashed with dilute HCl, 5% NaHCO3, and brine
4. 4
   DryingThe extract is dried over magnesium sulfate
5. 5
   Otherevaporated to dryness

Procedure

To a solution of 0.9 g (4.3 mmole) of 98% p-toluenesulfonyl chloride in 10 ml of dry pyridine at 0° is added 0.9 g (4.15 mmole) of 3-t-butoxycarbonylamino-2-hydroxymethyl-4-oxoazetidine. The mixture is stirred for 2 hr at 0° and then stored at 5° overnight. After addition of 0.5 ml of 85% lactic acid, the mixture is stirred for 1 hr, poured into ethyl acetate and washed with dilute HCl, 5% NaHCO3, and brine. The extract is dried over magnesium sulfate and evaporated to dryness to give 1.1 g (70%) of crystalline title product. Recrystallization from hexane-ethyl acetate gives an analytical sample, mp 160°-162° (d).

Source