VITAMIN B12S-PROMOTED MODEL REARRANGEMENT OF METHYLMALONATE TO SUCCINATE IS NOT A FREE-RADICAL REACTION

被引:21
作者
CHOI, GY [1 ]
CHOI, SC [1 ]
GALAN, A [1 ]
WILK, B [1 ]
DOWD, P [1 ]
机构
[1] UNIV PITTSBURGH, DEPT CHEM, PITTSBURGH, PA 15260 USA
关键词
Carbanion; Coenzyme B[!sub]12[!/sub; Pentenylmalonate; Radical trap; Tri-n-butyltin hydride;
D O I
10.1073/pnas.87.8.3174
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
To probe for free radical intermediates in the model methylmalonate to succinate rearrangements promoted by vitamin B12s, a model series with a pentenyl side chain radical trap has been devised. The control free radical, generated by tri-n-butyltin hydride treatment of bromomethylpentenylmalonate thioester, undergoes rapid cyclization to the six-membered ring, and, as anticipated, no succinate rearrangement product is detected. By contrast when the bromide is treated with vitamin B12s, little cyclized product is observed; the major product is the pentenyl succinate. This result demonstrates that the latter rearrangement does not follow a free radical pathway.
引用
收藏
页码:3174 / 3176
页数:3
相关论文
共 21 条
[11]   ON THE FORMATION OF FREE-RADICALS FROM ALKYLCOBALT COMPLEXES [J].
GIESE, B ;
HARTUNG, J ;
HE, JN ;
HUTER, O ;
KOCH, A .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1989, 28 (03) :325-327
[12]   FREE-RADICAL CLOCKS [J].
GRILLER, D ;
INGOLD, KU .
ACCOUNTS OF CHEMICAL RESEARCH, 1980, 13 (09) :317-323
[13]   MECHANISMS OF COENZYME-B12 - DEPENDENT REARRANGEMENTS [J].
HALPERN, J .
SCIENCE, 1985, 227 (4689) :869-875
[14]   The conditions underlying the formation of unsaturated and of cyclic compounds from halogenated open-chain derivatives Part I Products derived from a-halogenated glutaric acids [J].
Ingold, CK .
JOURNAL OF THE CHEMICAL SOCIETY, 1921, 119 :305-329
[15]  
NEUMANN WP, 1987, SYNTHESIS-STUTTGART, P665
[16]  
Retey J., 1982, B12, VII, P357
[17]   VITAMIN-B12 - CATALYST FOR A NON-ENZYMIC CARBON-SKELETON MODEL REARRANGEMENT [J].
SCOTT, AI ;
KANG, J ;
DOWD, P ;
TRIVEDI, BK .
BIOORGANIC CHEMISTRY, 1980, 9 (02) :227-230
[18]   MECHANISM OF ACTION OF COENZYME B-12 - ROLE OF THIOESTER IN A NONENZYME MODEL REACTION FOR COENZYME B-12 DEPENDENT ISOMERIZATION OF METHYLMALONYL COENZYME-A TO SUCCINYL COENZYME-A [J].
SCOTT, AI ;
KANG, K .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1977, 99 (06) :1997-1999
[19]   MECHANISM OF ACTION OF COENZYME B-12 - OVERALL ANIONIC MECHANISM FOR CARBON-SKELETON REARRANGEMENT IN A MODEL REACTION [J].
SCOTT, AI ;
KANG, J ;
DALTON, D ;
CHUNG, SK .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (11) :3603-3604
[20]   FREE-RADICAL REARRANGEMENT INVOLVING THE 1,2-MIGRATION OF A THIOESTER GROUP - MODEL FOR THE COENZYME-B12 DEPENDENT METHYLMALONYL-COA MUTASE REACTION [J].
WOLLOWITZ, S ;
HALPERN, J .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1984, 106 (26) :8319-8321