Racemization in prins cyclization reactions

被引：105

作者：

Jasti, Ramesh ^{[1
]}

Rychnovsky, Scott D. ^{[1
]}

机构：

[1] Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2006年 / 128卷 / 41期

关键词：

D O I：

10.1021/ja064783l

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Isotopic labeling experiments were performed to elucidate a new mechanism for racemization in Prins cyclization reactions. The loss in optical activity for these reactions was shown to occur by 2-oxonia-Cope rearrangements by way of a (Z)-oxocarbenium ion intermediate. Reaction conditions such as solvent, temperature, and the nucleophile employed played a critical role in whether an erosion in enantiomeric excess was observed. Additionally, certain structural features of Prins cyclization precursors were also shown to be important for preserving optical purity in these reactions.

引用

收藏

页码：13640 / 13648

页数：9

相关论文

共 67 条

[41] PI-CYCLIZATIONS OF ALPHA-METHOXYCARBONYL OXYCARBENIUM IONS - SYNTHESIS OF OXACYCLIC CARBOXYLIC ESTERS [J].

LOLKEMA, LDM ;

HIEMSTRA, H ;

SEMEYN, C ;

SPECKAMP, WN .

TETRAHEDRON, 1994, 50 (24) :7115-7128

[42] Synthesis of (-)-centrolobine by prins cyclizations that avoid racemization [J].

Marumoto, S ;

Jaber, JJ ;

Vitale, JP ;

Rychnovsky, SD .

ORGANIC LETTERS, 2002, 4 (22) :3919-3922

[43] Syn- and anti-selective Prins cyclizations of δ,ε-unsaturated ketones to 1,3-halohydrins with Lewis acids [J].

Miles, RB ;

Davis, CE ;

Coates, RM .

JOURNAL OF ORGANIC CHEMISTRY, 2006, 71 (04) :1493-1501

[44] The silylalkyne-prins cyclization:: Stereoselective synthesis of tetra- and pentasubstituted halodihydropyrans [J].

Miranda, PO ;

Ramírez, MA ;

Martín, VS ;

Padrón, JI .

ORGANIC LETTERS, 2006, 8 (08) :1633-1636

[45] Iron(III)-catalyzed Prins-type cyclization using homopropargylic alcohol:: A method for the synthesis of 2-alkyl-4-halo-5,6-dihydro-2H-pyrans [J].

Miranda, PO ;

Díaz, DD ;

Padrón, JI ;

Bermejo, J ;

Martín, VS .

ORGANIC LETTERS, 2003, 5 (11) :1979-1982

[46] Absolute configuration of phorboxazoles A and B from the marine sponge, Phorbas sp .2. C43 and complete stereochemistry [J].

Molinski, TF .

TETRAHEDRON LETTERS, 1996, 37 (44) :7879-7880

[47] New concept in the allylation of aldehydes: Regiospecific allylation of aldehydes by an allyl-transfer reaction of homoallylic alcohols [J].

Nokami, J ;

Yoshizane, K ;

Matsuura, H ;

Sumida, S .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (26) :6609-6610

[48] TRIFLUOROACETOLYSIS OF EXO-2-NORBORNYL AND ENDO-2-NORBORNYL AND RELATED TOSYLATES [J].

NORDLAND.JE ;

GRUETZMA.RR ;

KELLY, WJ ;

JINDAL, SP .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1974, 96 (01) :181-185

[49] Scope and facial selectivity of the prins-pinacol synthesis of attached rings [J].

Overman, LE ;

Velthuisen, EJ .

JOURNAL OF ORGANIC CHEMISTRY, 2006, 71 (04) :1581-1587

[50] Strategic use of pinacol-terminated prins cyclizations in target-oriented total synthesis [J].

Overman, LE ;

Pennington, LD .

JOURNAL OF ORGANIC CHEMISTRY, 2003, 68 (19) :7143-7157

← 1 2 3 4 5 6 7 →