Reaction #2013

Reaction equation

BOP

D-Homophenylalanine allyl ester

triethylamine

4-(benzyloxycarbonylamino)-4-methyl-pentanoic acid

→

(R)-α-[(4-Benzyloxycarbonylamino-4-methyl-1-oxopentyl)amino]benzenebutanoic acid allyl ester

Solvents

methylene chloride

methylene chloride

Conditions

Workup

1. 1
   workup.STIRRINGthis reaction mixture stirred at room temperature for 17 h
2. 2
   OtherThe reaction was quenched
3. 3
   workup.ADDITIONby adding brine
4. 4
   Otherthe products of the reaction isolated by extraction with methylene chloride (3×15 ml)
5. 5
   Dryingdried with anhydrous magnesium sulfate powder
6. 6
   Filtrationfiltered
7. 7
   Otherevaporated under reduced pressure
8. 8
   OtherA thick golden yellow gum was obtained which
9. 9
   Otherwas purified by column chromatography on silica gel
10. 10
    OtherThe product (182 mg; 48.9%) was isolated as a pale yellow gum

Procedure

D-Homophenylalanine allyl ester (175 mg; 0.80 mmol) (see Example 9, Step B), triethylamine (222 μl; 1.59 mmol) were dissolved in dry methylene chloride (2 ml) and 4-(benzyloxycarbonylamino)-4-methyl-pentanoic acid (211 mg; 0.80 mmol) added. The solution was stirred at room temperature and BOP (353 mg; 0.80 mmol) was added over 5 minutes, and this reaction mixture stirred at room temperature for 17 h. The reaction was quenched by adding brine and then the products of the reaction isolated by extraction with methylene chloride (3×15 ml). The methylene chloride layers were combined and dried with anhydrous magnesium sulfate powder, filtered and evaporated under reduced pressure. A thick golden yellow gum was obtained which was purified by column chromatography on silica gel using ethyl acetate and hexanes 1:2 v/v. The product (182 mg; 48.9%) was isolated as a pale yellow gum. FAB-MS:- calculated for C27H34 N2O5 466.3; found 467.7 (M+1).

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