[en] Methyl substituted seven-membered ring carbonate (7CC), namely 4-methyl-1,3-dioxepan-2-one (α-Me7CC) have been synthesized in good yield (up to 50%) upon cyclization of the corresponding α-diols issued from green renewable acid. (^Immortal⁾ Ring-opening polymerization (iROP) of this monomer has been carried out using various catalysts combined with an alcohol acting as a co-initiator and a chain transfer agent. The Lewis acid Al(OTf)₃ or the organometallic complexes [(BDI^iPr)Zn(N(SiMe₃)₂)] ((BDI^iPr) = 2-((2,6-diisopropylphenyl)amido)-4-((2,6- diisopropylphenyl)-imino)-2-pentene] and [(ONOO^tBu)Y(N(SiHMe₂)₂)(THF)] (ONOO^tBu = amino-alkoxy-bis( phenolate)) successfully afforded the corresponding poly(α-Me7CC) with quite good control and activities. Detailed microstructural analysis of the poly(a-Me7CC) using ¹H and ¹³C NMR and MALDI-TOF-MS techniques revealed the higher regioselectivity -with preferential ring-opening at the most hindered oxygen-acyl O-C(O)O bond, i.e. close to the α-Me substituent- of the zinc-based system followed by the yttrium as compared to the lack of selectivity of the aluminum one, in the ROP of α-Me7CC. (author)