Benzyl P-malolactonate

Four-membered ring lactones 3-propiolactone (P-PL) [68-70], P-butyrolactone (P-BL) [71-76], benzyl P-malolactonate (BBM) [77] and a-methyl-P-propiolactone (MPL) [78, 79] were polymerised using different lipases (Table 12.5). 

Figure 9.1 Time-dependence of benzyl-P-malolactonate (MLABz) conversion in polyester as initiated by potassium 11-hydroxydodecanoate added with 18-crown-6 ether (HDD) in THF at 0°C for [MLABz]o of 0.2 mol I and various [MLABz]o/[HDD]o ratios (a) 24, (b) 48, (c) 73.

Anionic Ring-Opening Polymerization of Benzyl P-Malolactonate [27c]... 

In addition to BL, the lipase-catalyzed ROP of substituted four-membered lactones such as P-methyl-P-propiolactone and P-propiolactone was first reported by Nobes et al [84], followed by several studies with ( )-a-methyl-P-propiolactone [85], a-decenyl-P-propiolactone, a-dodecyl-P-propiolactone [86], and benzyl-P-D,L-malolactonate, among others [87]. 

An interesting derivative of PHB, poly(P-malic acid) (PMA), has been synthesized from -benzyl malolactonate followed by catalytic hydrogenolysis. PMA differs from PHB in that the -(CHa) substituent is replaced by — COOH [Kimura, 1993]. The introduction of pendant carboxylic acid group would make PMA more hydrophilic and easier to be absorbed. 

Guerin, P., Francillette, J., Brand, C.. and Vert, M. (1986) Benzyl esters of optically active malic acid stereocopohmers as obtained by ring-opening pohanerization of (R)-(+) and (S)-(-)-ben7.yI malolactonates. Makromol. Chem. Macromot. Ssmp., 6, 305-314. 

Propen-3-ol and 3-methyl-3-butenol have been used to introduce an unsaturation in P-substituted p-lactones according to the aspartic route (Figure 2). These new malolactonic esters have been polymerized or copolymerized with benzyl malolactonate leading to high molecular weight functional polyesters. 

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