Abstract
A library of bidentate diols, as well as tridentate triols and aminodiols, derived from (+)-sabinol, was synthesized in a stereoselective manner. Sabinol was transformed into allylic trichloroacetamide via Overman rearrangement of the corresponding trichloroacetimidate. After changing the protecting group to Boc, the enamine was subjected to stereospecific dihydroxylation with OsO4/NMO, resulting in the (1R,2R,3R,5R)-aminodiol diastereomer. The obtained primary aminodiol was transformed to a secondary analogue. The ring closure of the N-benzyl-substituted aminodiol with formaldehyde was investigated and regioselective formation of the spiro-oxazolidine ring was observed. Hydroboration or dihydroxylation of sabinol or its benzyl ether with OsO4/NMO resulted in the formation of sabinane-based diols and triols following a highly stereospecific reaction. Treatment of sabinol with m-CPBA afforded O-benzoyl triol as a diastereoisomer of the directly dihydroxylated product, instead of the expected epoxy alcohol. The resulting aminodiols, diol, and triols were applied as chiral catalysts in the reaction of diethylzinc and benzaldehyde from moderate to good selectivity.
Highlights
In recent years, the discovery and application of new chiral auxiliaries and catalysts have become a crucial question in stereoselective syntheses [1,2,3,4]
The planned aminodiols, diols, and triols may serve as useful building blocks for the synthesis of new heterocyclic ring systems and biologically active compounds
Acid-catalyzed removal of the protecting group resulted in primary aminodiol hydrochloride 7 with 41% overall yield
Summary
The discovery and application of new chiral auxiliaries and catalysts have become a crucial question in stereoselective syntheses [1,2,3,4]. Efficient, and commercially available chiral catalysts, natural chiral terpenes [5], including (+)-pulegone [6,7,8], α- and β-pinene [9,10,11,12,13,14], and fenchone-camphor [15,16,17,18,19] have proved to be excellent sources Starting from these readily available natural sources, several powerful chiral catalysts, including various di- and trifunctional synthons, such as 1,3-aminoalcohols and aminodiols, have been applied in stereoselective syntheses [5,20].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
