Enantioselective Synthesis of Antiepileptic Agent, (−)-Levetiracetam, through Evans Asymmetric Strategy

Table 1

Diastereoselective α-alkylation of 4a & 4b.

Entry no.	Starting material	R	Product	Observations^a	Yield^b (%)
1	4a	Ph	5a	Single diasteromer	81
2	4b	PhCH2	5b	Diastereomers mixture	53

^aObserved by monitoring on TLC and ^bisolated yield after purification.