Réaction #632034

Équation de réaction

compound ( 27 )

1-Hydroxy-(3S,4S)-2,5-Dioxo-3,4-dibenzoyloxypyrrolidine

thiocarbonate

O-(1-Isobutanoyloxyisobutoxy) S-Methyl Thiocarbonate

peracetic acid

peracetic acid

→

title compound ( 25 )

Rendement 25.7%

(1R)-1-[((3S,4S)-2,5-Dioxo-3,4-dibenzoyloxypyrrolidinyl)-oxycarbonyloxy]-2-methylpropyl 2-methylpropanoate

Rendement 25.7%

Solvants

dichloromethane

acetic acid

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAfter the addition
2. 2
   FiltrationThe resulting white precipitate was filtered
3. 3
   Lavagewashed successively with water
4. 4
   workup.ADDITIONa mixture of ether and hexane (1:2)
5. 5
   Autredried under vacuum
6. 6
   Autreto afford the crude title compound
7. 7
   AutreThis product was crystallized once from a mixture of ethyl acetate and hexane (1:1)

Mode opératoire

To a stirred solution of compound (27) (35 g, 98.6 mmol) and thiocarbonate (11) (34.6 g, 148 mmol) in dichloromethane at 0° C. was dropwise added a 32% solution of peracetic acid (300 mmol) in acetic acid over 2 h. The reaction temperature was kept below 35° C. during the addition of peracetic acid. After the addition was complete, the reaction mixture was stirred overnight at room temperature. The resulting white precipitate was filtered and washed successively with water, and a mixture of ether and hexane (1:2), then dried under vacuum to afford the crude title compound. This product was crystallized once from a mixture of ethyl acetate and hexane (1:1) to afford the title compound (25) (13.7 g, 25% yield). The diastereomeric purity of the product was determined to be 98.4% d.e. by HPLC using a chiral column. 1H NMR (CDCl3, 400 MHz): δ 1.06 (d, 6H), 1.22 (d, 3H), 1.22 (d, 3H), 2.20 (m, 1H), 2.64 (hept. 1H), 6.01 (br. s, 2H), 6.64 (d, 1H), 7.47 (m, 4H), 7.63 (m, 2H), 8.07 (m, 4H).

Source