How is 2-Methyl-2-propanyl 6-oxa-2,9-diazaspiro[4.5]decane-9-carboxylate (CAS: 637039-01-1) typically synthesized?

2-Methyl-2-propanyl 6-oxa-2,9-diazaspiro[4.5]decane-9-carboxylate (CAS: 637039-01-1) is synthesized via a multi-step reaction involving the formation of a 2,9-diazaspiro[4.5]decane ring followed by esterification. Common methods include the use of acyl chlorides or anhydrides as the carboxylic acid derivative. The reaction is typically performed in the presence of a solvent such as dichloromethane and a catalytic amount of a base like triethylamine. The yield and selectivity are generally good, with high purity products obtained.