Non-destructive Cleavage of N-Acylsultams Under Neutral Conditions: Preparation of Enantiomerically, Pure Fmoc-Protected α-Amino Acids

Article abstract of DOI:10.1002/hlca.19920750812

Heating diastereoisomerically pure N-acylsultams 3 or 4 with allyl alcohol/Ti(OR)4 efficiently yields sultams 1 or 2 and allyl esters 5.Esters 5 are hydrolyzed under nonbasic conditions in the presence of Wilkinson's catalyst to give enantiomerically and diastereoisomerically pure carboxylic acids 7.A series of <(fluoren-9-yl)methoxy>carbonyl-(Fmoc)-protected amino acids 14 were thus prepared from N-acylsultams 12.