Neighbouring hydroxy-group participation in the opening of epoxides by nucleophiles

1973 ◽  
pp. 839 ◽  
Author(s):  
Derek H. R. Barton ◽  
Yoram Houminer
Keyword(s):  
Hydroxy Group ◽  
Group Participation

scholarly journals Neighbouring Group Participation in the Methanolysis of a Vicinal Diepoxide

1999 ◽  
Vol 23 (6) ◽  
pp. 356-357
Author(s):  
James R. Hanson ◽  
Peter B. Hitchcock ◽  
Ismail Kiran
Keyword(s):  
Hydroxy Group ◽  
Group Participation ◽  
Neighbouring Group Participation

The tetracyanoethylene catalysed methanolysis of 17β-acetoxy-4β,5β:6α,7α-diepoxyandrostane afforded 17β-acetoxy-4α,7α-oxido-5β-hydroxy-6β-methoxyandrostane in which the methanolysis product of the 6α,7α-epoxide has participated in the cleavage of the 4β,5β-epoxide; the reaction is modified however by an adjacent 3β-hydroxy group.

Hydroxy-group participation in ester hydrolysis

1973 ◽  
pp. 1118 ◽  
Author(s):  
Brian Capon ◽  
Samuel T. McDowell ◽  
William V. Raftery
Keyword(s):  
Hydroxy Group ◽  
Ester Hydrolysis ◽  
Group Participation

Synthesis of 14-deoxy-14α-strophanthidin

1980 ◽  
Vol 45 (11) ◽  
pp. 2998-3007 ◽  
Author(s):  
Pavel Kočovský
Keyword(s):  
Acetic Acid ◽  
Hydroxy Group ◽  
Cyclic Ether ◽  
Hydroxy Derivative ◽  
Neighboring Group ◽  
Step Process ◽  
Group Participation ◽  
Hypobromous Acid ◽  
Characteristic Features ◽  
Neighboring Group Participation

A seventeen step synthesis of 3β,5-dihydroxy-19-oxo-5β,14α-card-20(22)-enolide (II, title compound) from 3β-benzoyloxy-5-pregnen-20-one (IV) is described. Characteristic features of this approach are the protection of the 19-hydroxy group as methyl ether, recovery of the hydroxyl and the introduction of 5β-hydroxyl on the basis of neighboring group participation. The 19-hydroxy group was regenerated in XIV by a two-step process: Addition of hypobromous acid to the 5,6-double bond leads to the 5α,6α-bromonium ion XV, which is cleaved with 5(O)n participation of the 19-methoxyl group to the cyclic ether XVI, the latter being converted to the 19-hydroxy derivative XVII by treatment with zinc and acetic acid. The 5β-hydroxy group was introduced by hypobromous acid addition to the 5,6-unsaturated 19-formate XVIII which proceeds with 6(O)π,n participation of the formate group (XVIII → XIX → XX).

ChemInform Abstract: HYDROXY-GROUP PARTICIPATION IN ESTER HYDROLYSIS

1973 ◽  
Vol 4 (33) ◽  
pp. no-no
Author(s):  
BRIAN CAPON ◽  
SAMUEL T. MCDOWELL ◽  
WILLIAM V. RAFTERY
Keyword(s):  
Hydroxy Group ◽  
Ester Hydrolysis ◽  
Group Participation
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