Use of biological systems for the preparation of chiral molecules. 3. Application in pheromone synthesis: preparation of sulcatol enantiomers

Enzymatic resolution of racemic sulcatol by lipase from Candida Antarctica in a large scale

“…The absolute configuration of (S)-(+)-2 was determined comparing the specific rotation sign measured for the product with that reported in the literature [9,20,22,24]. The absolute configuration of sulcatyl acetate (R)-(+)-3 was in full agreement with that previously reported [26].…”

“…The results obtained showed that the stereochemical preference of CALB for the sulcatol 2 was in accordance with the Kazlauskas rule [36]. By making a comparison between the obtained specific rotation values and those reported in the literature, sulcatol 2 was given the (S)-configuration [9,20,22,24], while the sulcatyl acetate 3 was assigned an (R)-configuration [26]. Figure 1 …”

“…The preparation of (S)-sulcatol 2 and (R)-sulcatyl acetate 3 on a small scale (35 mg mmol -1 ) has been described as CALB lipase, and chiral products were obtained with high enantiomeric excesses (> 98 percent ee) [21]. Biological reductions of sulcatone 1 have been described for the preparation of sulcatol 2 in good enantiomeric excesses (ee > 80-99 percent) [22][23]. The efficient non-enzymatic methodology of chemical kinetic resolution of (±)-sulcatol 2 using chiral aldehyde/In(OTf) 3 produced (R)-sulcatol 2 in high enantiomeric excess [24].…”

O emprego de fermento de pão, Saccharomyces cerevisiae, na síntese de feromônios

“…Uma outra espécie, G. retusus, besouros da ambrosia, importante praga nas florestas de coníferas da Costa do Pacífico Norte, é sensível apenas ao isômero S e a resposta é inibida pela ação do R 3,4 .…”

“…A rota sintética que fornece os compostos 28 e 29 se baseia no emprego do fermento de pão para a obtenção de dois intermediários através da síntese convergente 23 (Esquema 7). O sulcatol, (S)-(+)-6-metil-hept-5-en-2-ol (1) foi obtido por Belan et al 3 pela redução microbiológica altamente estereosseletiva com S. cerevisae 3 de 6-metil-hept-5-en-2-ona (30). O isômero R, entretanto, foi obtido utilizando outro microrganismo.…”