Alternative Synthesis of (-)-Geissman-Waiss Lactone, a Key Intermediate of Necine Bases
摘要:
A facile synthetic route to (-)-Geissman-Waiss lactone, a key intermediate of necine bases, was established by employing ring closing metathesis (RCM), followed by intramolecular Michael reaction of the resulting a,p-unsaturated lactone, as the key steps.
Modular Construction of Protected 1,2/1,3-Diols, -Amino Alcohols, and -Diamines via Catalytic Asymmetric Dehydrative Allylation: An Application to Synthesis of Sphingosine
A new enantioselective catalysis has been developed for the one-step construction of methylene-bridged chiral modules of 1,2- and 1,3-OH and/or NH function(s) from δ- or λ-OH/NHBoc-substituted allylicalcohols and “H2C═O”/“H2C═NBoc”. A protonic nucleophile, either in situ-generated CH2OH or CH2NHBoc, is intramolecularly allylated to furnish eight possible 1,2- or 1,3-O,O, -O,N, -N,O, and -N,N chiral
Asymmetric intramolecular amidation of N-(tert-butoxycarbonyl)-3-hydroxy-4-pentenylamine. A new entry to chiral building blocks for the synthesis of biologically active nitrogen-containing compounds
Sharpless reaction of racemic N-(tert-butoxycarbonyl)-3-hydroxy-4-pentenylamine (1) leads to both an asymmetric kinetic resolution to provide optically active 1, which was subsequently used for intramolecular amidomercuration, and asymmetric epoxidation followed by concomitant cyclization into optically active cis-3-hydroxy-2-(hydroxymethyl)pyrrolidine (3). Optically active 1 and 3 have been expediently used as chiral building blocks in the asymmetric synthesis of several biologically active natural products.
TAKAHATA, HIROKI;BANBA, YASUNORI;TAJIMA, MAYUMI;MOMOSE, TAKEFUMI, J. ORG. CHEM., 56,(1991) N, C. 240-245