4-Methylmorpholine → HCID 13685969, compound

Participants

Reaction Steps

This compound was prepared from 4.99 g (20 mmol) N-carbobenzoxy-L-proline, 2.73 g (20 mmol) isobutyl chloroformate, 2.02 g (20 mmol) N-methylmorpholine, and 1.78 g (20 mmol) d-(+)2-amino-1-butanol, substantially according to the mixed anhydride procedure described in Example 1. Crude product (5.16 g) was recrystallized from a mixture of 60 mL ethyl acetate and 15 mL n-hexane to give 4.18 g (13 mmol, 65%) of colorless, crystalline N-carbobenzoxy-L-prolyl-L-homoalaninol; m.p. 105.4°-106.3°, α25D-69.7 (C=1.04 g/100 mL in acetone). A stereochemical assignment for this product was based upon observed similarity of specific rotation to specific rotations measured for L-L isomers of carbobenzoxy-prolyl-leucinol (Example 1), carbobenzoxy-prolyl-valinol (Example 2) and carbobenzoxy-prolyl-alaninol (Example 5).

Provenance & Evidence