966-46-1Relevant articles and documents
Zn-Mediated Hydrodeoxygenation of Tertiary Alkyl Oxalates
Ye, Yang,Ma, Guobin,Yao, Ken,Gong, Hegui
supporting information, p. 1625 - 1628 (2021/01/18)
Herein we describe a general, mild, and scalable method for hydrodeoxygenation of readily accessible tertiary alkyl oxalates by Zn/silane under Ni-catalyzed conditions. The reduction method is suitable for an array of structural motifs derived from tertiary alcohols that bear diverse functional groups, including the synthesis of a key intermediate en route to estrone.
Total synthesis with a chirogenic opening move demonstrated on steroids with estrane or 18a-homoestrane skeleton
Quinkert,Del Grosso,Doring,Doring,Schenkel,Bauch,Dambacher,Bats,Zimmermann,Durner
, p. 1345 - 1391 (2007/10/02)
A concept of first choice for the synthesis of the title compounds had been proposed by Dane in the late 1930s. It was soon turned down, because the opening move - a chirogenic Diels-Alder reaction - did not work. With Lewis acids as mediators, however, a successful start has been achieved now. With Ti complexes of chelating ligands (Seebach's TADDOLs (= α,α,α',α'-tetraaryl-1,3-dioxolane-4,5-dimethanols)), enantioselective formation of the desired adducts does occur. Efficient total syntheses of 2 and 3a have been accomplished.
An Enantioselective Version of the AB + D --> ABCD-Type Stereoid Total Synthesis
Quinkert, Gerhard,Grosso, Michael del,Bucher, Astrid,Bauch, Markus,Doering, Wolfgang,et al.
, p. 3617 - 3620 (2007/10/02)
Diene 1 and dienophile 4a in a Diels/Alder reaction mediated by a chiral ligand-modified Lewis acid enantioselectively furnish adduct 5a (chem. yield: 64percent; e.e: 73percent), which after partial deoxygenation and final enantioselection by recrystallization affords 5b.The latter compound can easily be converted via Torgov's pentaenone 6a into estrogens or progestogens. Key Words: stereoid total synthesis, enantioselective Lewis acid-mediated Diels/Alder reaction
A Synthesis of (+/-)-Estrone Methyl Ether via the Tandem Cope-Claisen Rearrangement
Ziegler, Frederick E.,Lim, Hong
, p. 5229 - 5230 (2007/10/02)
A synthesis of (+/-)-estrone methyl ether (7b) is described that employs a new approach to the construction of the estrogen skeleton invoking the tandem Cope-Claisen rearrangement.
TANDEM MICHAEL-MICHAEL-RING CLOSURE (MIMIRC) REACTIONS; ONE-POT STEROID TOTAL SYNTHESIS-(+/-)-9,11-DEHYDROESTRONES
Posner, Gary H.,Mallamo, John P.,Black, Alison Y.
, p. 3921 - 3926 (2007/10/02)
A new sequence of reactions involving tandem Michael-Michael-ring closure (MIMIRC) has been developed for efficient formation of three C-C bonds in one reaction vessel.The terminal ring closure reaction proceeds via either a 1,3- or a 1,6-cyclization, and this methodology also serves for construction of quaternary C centers.The usefulness of MIMIRC reactions is demonstrated by efficient assembly of cyclopropyl ketones and of trans-1-hydrindanones such as (+/-)-9,11-dehydroestrone 1b.This one-pot approach represents the shortest known convergent total synthesis of a steroid, and subsequent straightforward transformations lead directly to natural (+/-)-estrone.
7,7A-Dihydro-4-[2-(3-alkoxyphenyl)-2-hydroxyethyl]-7a-alkyl-1, 5(6H)-indandiones,3,4,8,8a-tetrahydro-5-[2-(3-alkoxyphenyl)-2-hydroxyethyl]-8a-alkyl-1,6(7H)-naphthalenediones and processes for the preparation thereof utilizing asymmetric induction
-
, (2008/06/13)
A multi-step, stereospecific total synthesis of steroids is disclosed. The starting materials for this process are the relatively inexpensive and readily available m-alkoxy acetophenones. The process is suitable for the preparation of racemic or optically
