PERICYCLIC-REACTIONS IN NATURE - EVIDENCE FOR A SPONTANEOUS [1.7]-HYDROGEN SHIFT AND AN 8-PI-E ELECTROCYCLIC RING-CLOSURE IN THE BIOSYNTHESIS OF OLEFINIC HYDROCARBONS FROM MARINE BROWN-ALGAE (PHAEOPHYCEAE)

被引：36

作者：

POHNERT, G ^{[1
]}

BOLAND, W ^{[1
]}

机构：

[1] INST ORGAN CHEM & BIOCHEM,D-53121 BONN,GERMANY

来源：

TETRAHEDRON | 1994年 / 50卷 / 34期

关键词：

D O I：

10.1016/S0040-4020(01)81756-7

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The stereochemistry of the algal C11H16 hydrocarbon giffordene 3 results from a spontaneous [1,7]-sigmatropic hydrogen shift of the thermolabile (1,3Z,5Z,8Z)-undecatetraene 8. An 8 pi e electrocyclisation of (1,3Z,5Z,7E)-nonatetraene 9 is substantiated for the biosynthesis of 7-methylcyclooctatriene 5, a product of the Mediterranean brown alga Cutleria multifida. Low temperature syntheses (-30 degrees C) of the thermolabile precursors 8 and 9 are described. The activation energies of the [1,7]-sigmatropic hydrogen shift 8-->3 (E(a) = 67.4 kJ mol(-1)) and of the 8 pi e electrocyclisation 9-->5 (E(a) = 59.4 kJ mol(-1)) are the lowest values currently known for natural pericyclic reactions.

引用

页码：10235 / 10244

页数：10

共 28 条

[1] CYCLO-ADDITION OF SINGLET OXYGEN AND 4-PHENYL-4H-1,2,4-TRIAZOLE-3,5-DIONE TO 7-SUBSTITUTED 1,3,5-CYCLOOCTATRIENES [J].