Nojima, Masatomo’s team published research in Chemistry Letters in 1972 | CAS: 6553-72-6

Ethyl 1-methylcyclopentanecarboxylate(cas: 6553-72-6) is a member of cyclopentanes. Although cyclopentane itself doesn’t have a single highly favoured conformation, a substituent on the cyclopentane ring can upset the balance of strains thereby favouring either the envelope or the half-chair.Synthetic Route of C9H16O2

The author of 《Carbonylation in liquid sulfur dioxide. IV. Carbonylation in the antimony pentachloride-liquid sulfur dioxide system. Carboxylic acid ester synthesis from alkyl chlorosulfite and dialkyl sulfite》 were Nojima, Masatomo; Shiba, Fumiaki; Tokura, Niichiro. And the article was published in Chemistry Letters in 1972. Synthetic Route of C9H16O2 The author mentioned the following in the article:

The carbonylation of BuBr, BuOSOCl, Me(CH2)3OS(O)(CH2)3Me, and PrOSOCl in SbCl5-SO2(1)-EtOH at -70° gave 5% EtCHMeCO2Et (I), 66% I, 75% BuCO2Et, and 65% PrCO2Et, resp. Similar treatment of cyclohexyl chloride, cyclohexyl chlorosulfite, and dicyclohexyl sulfite gave 8% Et cyclohexanecarboxylate (II) and 23% Et 1-methylcyclopentane carboxylate (III); 19% II and 37% III; and 53% II and 3% III; resp. The experimental process involved the reaction of Ethyl 1-methylcyclopentanecarboxylate(cas: 6553-72-6Synthetic Route of C9H16O2)

Ethyl 1-methylcyclopentanecarboxylate(cas: 6553-72-6) is a member of cyclopentanes. Although cyclopentane itself doesn’t have a single highly favoured conformation, a substituent on the cyclopentane ring can upset the balance of strains thereby favouring either the envelope or the half-chair.Synthetic Route of C9H16O2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics