Deoxygenation of aliphatic acetate derivatives using electrogenerated organic amalgams
摘要:
An electrochemical deoxygenation reaction of aliphatic acetates has been developed, using electrogenerated organic amalgams (R4N-Hg). This methodology led us to obtain the deoxygenated product and the alcohol in a 1:1 ratio with total transformation of the starting compound. Examples Using the acetates of sarsasapogenin, diosgenin. 16-dehydro-pregnanolone and argentatine A, show the applications and some limitations of this electrochemical reaction. (C) 2002 Elsevier Science Ltd. All rights reserved.
subjected to DMTST-mediated glucosylation for the synthesis of the chacotriose-substituted compound 3. For a selective 2,4-di-rhamnosylation of the dihydrodiosgenin glucopyranoside, differentiation of the glucose OH groups was achieved by selectivebenzoylation with 1-(benzoyloxy)benzotriazole. Reaction of the 3,6-di-O-benzoate 32 with the perbenzoylated ethyl thiorhamnopyranoside donor 15 gave the 2
[EN] DIOSGENIN ACETATE-ISOXAZOLE DERIVATIVES, PROCESS FOR PREPARATION THEREOF AND THEIR ANTIFUNGAL ACTIVITY<br/>[FR] DÉRIVÉS D'ACÉTATE DE DIOSGÉNINE-ISOXAZOLE, PROCÉDÉ POUR LEUR PRÉPARATION ET LEUR ACTIVITÉ ANTIFONGIQUE
申请人:COUNCIL SCIENT IND RES
公开号:WO2016135749A1
公开(公告)日:2016-09-01
This invention also relates to novel class of diosgenin acetate-Isoxazole and the synthesis of diosgenin acetate-Isoxazole starting from Diosgenin and its relatives with five (5) synthetic routes, acetylation (A), F-ring opening of diosgenin acetate (B), Oxidation of the hydroxyl group on C-26 of E-ring manipulation of diosgenin acetate (C), Formation of oxime (D) and Isoxazole formation on C-26 of E-ring manipulation of diosgenin acetate (E) having potent Antifungal activity against Alternariaalternate fungus.
A revisitation of the clemmensen reduction of diosgenin. characterization of byproducts and their use in the preparation of (25R)-26-hydroxysterols.
作者:Yuan Ni、Hong-Seok Kim、K. William、Wilson Alemka Kisic、George J. Schroepfer
DOI:10.1016/s0040-4039(00)79201-x
日期:1993.6
Four major byproducts of the Clemmensenreduction of diosgenin have been isolated and identified: (25R)-17 β-methyl-18-nor-17α-cholesta-5,13-diene-3 β,26-diol, dihydrodiosgenin, (22E,25R)-cholesta-5,22-diene-3 β,16β,26-triol, and its 22Z isomer. These byproducts were used to prepare deuterium- and tritium-labeled (25R)-26-hydroxycholesteroi (3) and Δ22 analogs of 3.
Synthesis of dimeric steroids as components of lipid membranes
作者:Jacek W. Morzycki、Sławomir Kalinowski、Zenon Łotowski、Joanna Rabiczko
DOI:10.1016/s0040-4020(97)00669-8
日期:1997.7
The synthesis of three dimeric steroids 1,2, and 3, as components of artificial lipid bilayer membranes, is described. Di(3β-hydroxyfurost-5-en-26-yl) (1) was obtained from diosgenin by reductive fission of a ring F, substitution of -OH by -l, and the Wurtz reaction. Two other dimers 2 and 3 were synthesised from the pregnanoic ester 10 by an “alkylation-reduction” procedure.
Aiming towards spiroketal-modified artificial cephalostatin molecules, two orthogonal approaches were investigated. First, the introduction of 17-O-functionality into hecogenin derivatives with a closed spiroketal moiety was accomplished by different remote-oxidation procedures. These allowed the synthesis of tetradecacyclic artificial cephalostatin molecules with improved tumor-inhibiting properties. Second, a novel reduction-oxidation pathway for spiroketal opening in sapogenins was discovered, which should provide the basis for a broad access towards spiroketal-modified building blocks for cephalostatins.