Stereoselective synthesis of thiaerythrinanes based on an α-amidoalkylation/RCM approach
摘要:
Parham cyclisation-intermolecular alpha-amidoalkylation and nucleophilic addition-intramolecular alpha-amidoalkylation sequences constitute diastereocomplementary routes to 1,10b-cis and trans thiazolo[4,3-a]isoquinolinones. These thiazolidinediones, that incorporate allyl groups at C-1 and C-10b, are efficient precursors of thiacrythrinanes by ring-closing metathesis reactions. (c) 2007 Elsevier Ltd. All rights reserved.
A Convenient Synthesis of 1,1-Disubstituted 1,2,3,4-Tetrahydroisoquinolines via Pictet-Spengler Reaction Using Titanium(IV) Isopropoxide and Acetic-Formic Anhydride.
A synthesis of 1,1-disubstituted 1,2,3,4-tetrahydroisoquinolines (6) was achieved in a highly efficient manner via Pictet-Spengler reaction of arylethylamines (1) and acyclic and cyclic ketones (2) using titanium (IV) isopropoxide and acetic-formic anhydride. The cyclization of the in situ formed acyliminium ion (4) to N-formyl 1,2,3,4-tetrahydroisoquinoline (5) was greatly facilitated by using trifluoroacetic
Parham cyclisation-intermolecular alpha-amidoalkylation and nucleophilic addition-intramolecular alpha-amidoalkylation sequences constitute diastereocomplementary routes to 1,10b-cis and trans thiazolo[4,3-a]isoquinolinones. These thiazolidinediones, that incorporate allyl groups at C-1 and C-10b, are efficient precursors of thiacrythrinanes by ring-closing metathesis reactions. (c) 2007 Elsevier Ltd. All rights reserved.