Non-catalytic synthesis of 2-acetamido-2,3-dideoxy-D-erythro-hex-2-enofuranose (Chromogen I) and 3-acetamido-5-(1′,2′-dihydroxyethyl)furan (Chromogen III) from N-acetyl-D-glucosamine (GlcNAc) was achieved, with the highest yields of 23.0% and 23.1%, respectively, in high-temperature water at 120–220 °C and 25 MPa with a reaction time of 7–39 s.
Haber-independent, asymmetric synthesis of the marine alkaloid <i>epi</i>-leptosphaerin from a chitin-derived chiral pool synthon
作者:Jessica C. Neville、Michelle Y. Lau、Tilo Söhnel、Jonathan Sperry
DOI:10.1039/d2ob01251k
日期:——
limit routine entry into enantiopure, bio-based N-chemical space. Herein, dihydroxyethyl acetamidofuran (Di-HAF), a chiralsynthon readily available from chitin, has been transformed into the marine alkaloid epi-leptosphaerin. This work extends the fledgling Haber-independent synthesis concept to enantiopure chemical space not routinely accessible from existing achiral platforms.
几丁质衍生平台正在成为有价值的化学实体,用于在独立于 Haber 氨的过程中构建含氮精细化学品。然而,该领域的大部分工作都集中在限制常规进入对映体纯生物基 N 化学空间的非手性平台上。在此,二羟乙基乙酰氨基呋喃 (Di-HAF) 是一种容易从几丁质中获得的手性合成子,已被转化为海洋生物碱epi -leptosphaerin。这项工作将羽翼未丰的独立于 Haber 的合成概念扩展到对映体纯化学空间,这些空间通常无法从现有的非手性平台获得。
π-Facial selectivity in the Diels–Alder reaction of glucosamine-based chiral furans and maleimides
作者:Cornelis H. M. van der Loo、Rutger Schim van der Loeff、Avelino Martín、Pilar Gomez-Sal、Mark L. G. Borst、Kees Pouwer、Adriaan J. Minnaard
DOI:10.1039/d2ob02221d
日期:——
feedstocks are a versatile class of bio-renewable building blocks and have been used extensively to access 7-oxanorbornenes via Diels–Alder reactions. Due to their substitution patterns these furans typically have two different π-faces and therefore furnish racemates in [4 + 2]-cycloadditions. We report the use of an enantiopure glucosamine derived furan that under kinetic conditions predominantly affords
The dehydration of <i>N</i>-acetylglucosamine (GlcNAc) to enantiopure dihydroxyethyl acetamidofuran (Di-HAF)
作者:Cornelis H. M. van der Loo、Mark L. G. Borst、Kees Pouwer、Adriaan J. Minnaard
DOI:10.1039/d1ob02004h
日期:——
optimized conditions, GlcNAc dehydrates in pyridine in the presence of phenylboronic acid and triflic acid to afford Di-HAF in 73% yield and 99.3% ee in just 30 minutes. This protocol opens the door for further research on this bio-renewable building block which is now available as a chiral pool synthon. A plausible mechanism of its formation and of the subsequent dehydration of Di-HAF into well-known