9-Phenyl-9-fluorenol → Nalpha-(9-fluorenylmethoxycarbonyl)-O-(9-phenyl-9H-fluoren-9-yl)-L-serine methyl ester

Participants

Reaction Steps

A solution of 6.2 g (24 mmol) of 9-phenyl-9H-fluoren-9-ol (Example 1b) and 6.8 g (20 mmol) of Nα -(9-fluorenylmethoxycarbonyl)-L-serine methyl ester in benzene (150 mL) was placed in a round bottomed flask fitted with a Dean-Stark trap. Two drops of concentrated sulfuric acid were added and the mixture heated under reflux with stirring for 1 h. Removal of the solvent under vacuo gave the crude Nα -(9-fluorenylmethoxycarbonyl)--O--(9-phenyl-9H-fluoren-9-yl)-L-serine methyl ester which was subjected to the Fmoc deprotection in Step 2 without further purification.

Provenance & Evidence