We describe in this paper the synthesis of compound 1 (R116301), which was developed to prepare pilot scale quantities (20–50 kg) of drug substance. The synthesis involves the s BuLi deprotonation of Boc-protected piperidone acetal 2, followed by benzaldehyde addition and ring closure to cyclic carbamate 4. Piperidine acetal 5 is resolved with Brown's acid and acylated. The ketone obtained after piperidine acetal deprotection undergoes reductive ...