Maxime Moreaux, Guillaume Bonneau, A. Peru
Jan 8, 2019
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0
Influential Citations
10
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Journal
European Journal of Organic Chemistry
Abstract
: A diastereoselective chemo-enzymatic synthetic pathway to D-(+)-ribono-1,4-lactone, a versatile chiral sugar derivative widely used for the synthesis of various natural products, has been designed from cellulose-based levoglucosenone ( LGO ). This route involves a sustainable Baeyer-Villiger oxidation of LGO to produce enantiopure (S)- g -hydroxymethyl-α,β-butenolide ( HBO ) that is further functionalized with various protecting groups to provide 5- O -protected D-(+)-ribono-1,4-lactones. The resulting 5- O -protected lactones then undergo a diastereoselective and high yielding syn -dihydroxylation of the a , b unsaturated lactone moiety followed by a deprotection step to give D-(+)-ribono-1,4-lactone. Through this 4-step synthetic route from LGO , D-(+)-ribono-1,4-lactone is obtained with d.r. varying from 82:18 to 97:3 and in overall yields between 32 and 41% depending on the protecting group used. Moreover, valuable synthetic intermediates 5- O - tert -butyldimethylsilyl-, 5- O - tert -butyldiphenylsilyl- as well as 5- O -benzyl-ribono-1,4-lactones are obtained in 3 steps from LGO in 58, 61 and 40%, respectively. Our team recently developed and green syntheses of optically pure from LGO using Baeyer-Villiger oxidations. Dedicated to the development of valuable applications of this platform molecule, our team then designed and optimized the chemo-enzymatic synthesis of (S)-dairy lactone, 12 a flavor used in food applications for its fruity odor and creamy dairy-like taste. This four-step synthetic route from cellulose-based levoglucosenone ( LGO ) involving (i) H 2 O 2 -mediated Baeyer-Villiger oxidation and (ii) diastereoselective and high yielding modified-Upjohn syn -dihydroxylation as key steps allows to access D-(+)-ribono-1,4-lactone with good to excellent diastereoselectivity and in good overall yields using TBDMS (44% yield, d.r. ca. 94:6), TBDPS (38%, d.r. ca. 94:6) and Bn (31%, d.r. ca. 80:20) protecting group, respectively. Although this new route does not compete with the one-step oxidation of D-ribose into D-(+)-ribono-1,4-lactone (ca. 65%) in terms of yield, diastereoselectivity and number of steps, not only it uses LGO , a cheaper renewable starting material, but it also allows the straightforward synthesis of 5- O- silylated and benzylated ribono-1,4-lactones which are valuable intermediates for the synthesis of high value added chemicals such as bioactive compounds and functional additives for drugs, food, feed or cosmetics.