Microwave-assisted solvent-free lipase catalyzed transesterification of β-ketoesters

Figures & data

Figure 1.  Conversion in transesterification of 3-oxobutanoate with 2- and 3-pentanol, yielding compounds 2 and 3, respectively. Microwave irradiation in solvent-free conditions. Control experiments performed in the absence of enzyme.

short-legendScheme 1. Transesterification of 1 and 4–7 with 2- and 3-pentanol as nucleophiles, CAL-B as catalyst, solvent-free conditions, and microwave irradiation.

Table 1. Conversions obtained by means of transesterification of 1 and 4–7 with 2- and 3-pentanol as nucleophiles, CaL-B as catalyst, solvent-free conditions, and microwave irradiation in a monomode laboratory reactor. Reaction time: 2 hours.

Entry	Substrate	Product	Temp. (°C)	Yielda (%)	Entry	Substrate	Product	Temp. (°C)	Yielda (%)
1	1	2	50	92	11	5	3	50	15
2	1	2	70	67	12	5	3	70	43
3	1	3	50	95	13	6	10	50	96
4	1	3	70	59	14	6	10	70	59
5	4	8	50	14	15	6	11	50	97
6	4	8	70	21	16	6	11	70	85
7	4	9	50	6	17	7	12	50	90
8	4	9	70	11	18	7	12	70	81
9	5	2	50	18	19	7	13	50	92
10	5	2	70	4	20	7	13	70	79
^aIsolated yield.