Tetrahedron letters

Novel chloroanthracyclines from acetal-alkene cyclization

…, SE Holroyd, M Johnson, PS Rutledge, PD Woodgate

Index: Brown, E. G.; Cambie, R. C.; Holroyd, S. E.; Johnson, M.; Rutiedge, P. S.; Woodgate, P. D. Tetrahedron Letters, 1989 , vol. 30, # 35 p. 4735 - 4736

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Citation Number: 7

Abstract

Abstract Quinizarin is converted in seven steps into the homochiral acetal (3) in 69% yield. Methallylation of (3) and reductive Claisen rearrangement gives (4) which is converted into four novel diastereomeric 9-chloroanthracyclines (7–10) by an unprecedented intramolecular acetal-alkene cyclization mediated by tin (IV) chloride in DMF.