ASYMMETRIC INDUCTION IN MN(III)-BASED OXIDATIVE FREE-RADICAL CYCLIZATIONS OF PHENYLMENTHYL ACETOACETATES AND 2,5-DIMETHYLPYRROLIDINE ACETOACETAMIDES

被引：67

作者：

ZHANG, QW ^{[1
]}

MOHAN, RM ^{[1
]}

COOK, L ^{[1
]}

KAZANIS, S ^{[1
]}

PEISACH, D ^{[1
]}

FOXMAN, BM ^{[1
]}

SNIDER, BB ^{[1
]}

机构：

[1] BRANDEIS UNIV,DEPT CHEM,WALTHAM,MA 02254

来源：

JOURNAL OF ORGANIC CHEMISTRY | 1993年 / 58卷 / 27期

关键词：

D O I：

10.1021/jo00079a006

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Mn(III)-based oxidative free-radical cyclization of phenylmenthyl ester 1e afforded 90% of 13 with 86% de. Cyclization of 31b provided 56% of (+)-podocarpic acid precursor 32e with 82% de. The direction of de was opposite in these two cases. Oxidative cyclization of a-methyl beta-keto ester 44b gave a 1:1.6 mixture of 46b and 47b while alpha-propyl beta-keto ester 44d produced a > 10:1 mixture of 46d and 47d indicating that the extent and direction of de is dependent on the size of the alpha-substituent The reaction proceeds through transition states 12 and 56 with large alpha-substituents and through transition states 19 and 57 with small a-substituents. The de depends on the double-bond substitution pattern as shown by the decreased de with 37b and 37d, and selectivity in the 5-exo cyclization of 64b, 65b, 70b, and 71b is low.

引用

页码：7640 / 7651

页数：12

共 57 条

[31] ENANTIOSELECTIVE 1,4-ADDITIONS OF ORGANOMETALLIC COMPOUNDS TO CONJUGATED SYSTEMS IN THE CHIRAL MEDIUM DDB [J].