Synthesis of chiral building blocks using Pseudomonas Fluorescens lipase catalyzed asymmetric hydrolysis of Meso diacetates

Synthetic avenues towards a tetrasaccharide related to Streptococcus pneumonia of serotype 6A

“…For acceptor 7 ( Fig. 2 ) ribitol 17 was converted to its corresponding diisopropylidene derivative 18 [ 37 ] in the presence of dimethoxypropane and p TSA in acetone. Treatment with NapBr and NaH in DMF gave compound 19 in 93% yield.…”

Applications of Wittig Reaction in the Total Synthesis of Natural Macrolides

“…A spontaneously reaction of the hydroxyaldehyde 41 using the Bestmann ylide directly gave the 12-membered lactone 42. [93] Noticeably, hydroxyaldehyde 41 produced a stabilized ylide spontaneously from the unmasked hydroxyl attacking the electrophilic ketene carbon followed by concomitant intramolecular Wittig olefination of the Racetoxyaldehyde to effect macrocyclization, giving the 12membered lactone 42 in 62% yield with whole E selectivity. The latter using Pseudomonas fluorescens lipase [94] (mild enzymatic deacetylation) afforded (+)-patulolide C 43 in 49% overall yields (Scheme 10).…”

“…The latter using Pseudomonas fluorescens lipase [94] (mild enzymatic deacetylation) afforded (+)-patulolide C 43 in 49% overall yields (Scheme 10). [93] The total synthesis of (+)-patulolide C 43, naturally occurring 12-membered ring bearing macrolides, was performed by using enantiopure (R)-(+)-γ-valerolactone and R-(+)-epichlorohydrin as chiral synthons. This approach is a convergent method in which two advanced intermediates were provided individually using the chiral synthons and coupled to provide the framework of patulolide C 43.…”

A new mechanism of enantioselectivity toward chiral primary alcohol by lipase from Pseudomonas cepacia

“…These alcohols could only be resolved by a limited number of lipases including PcL [11,12]. Although by these lipases, only a small number of primary alcohols could be recognized, and even toward this small number of alcohols, the lipases' enantiopreference did not obey Kazlauskas' Rule [13][14][15][16][17]. In the present contribution, enantioselectivity by PcL toward 14 pairs of different chiral primary alcohol esters was investigated.…”