An approach to the C(10)–C(16) fragment of the bryostatins: stereoselective exocyclic double-bond formation by vinyl radical cyclization

1998 ◽  
pp. 2853-2864 ◽  
Author(s):  
Robert J. Maguire ◽  
Simon P. Munt ◽  
Eric J. Thomas
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Radical Cyclization ◽  
Exocyclic Double Bond ◽  
Vinyl Radical

Genome mining of cryptic tetronate natural products from a PKS-NRPS encoding gene cluster in Trichoderma harzianum t-22

2021 ◽  
Vol 19 (9) ◽  
pp. 1985-1990
Author(s):  
Yiguang Zhu ◽  
Junfeng Wang ◽  
Pengyun Mou ◽  
Yan Yan ◽  
Mengbin Chen ◽  
...  
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Gene Cluster ◽  
Trichoderma Harzianum ◽  
Bond Formation ◽  
Genome Mining ◽  
Exocyclic Double Bond ◽  
Encoding Gene

The gene cluster of trihazones was identified from Trichoderma harzianum t-22 and heterologously activated in Aspergillus nidualns. The α-KG dependent dioxygenase ThnC was confirmed to catalyze exocyclic double bond formation.

Multiple Carbon Bond Formation Via the Radical Cyclization of Cycloalkenol Acetals. Application to trans Hydrindan Steroid Precursors

1992 ◽  
Vol 45 (1) ◽  
pp. 275 ◽  
Author(s):  
G Stork ◽  
PJ Franklin
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Carbon Chain ◽  
Radical Cyclization ◽  
Carbon Bond ◽  
Single Operation ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds

The cyclization of the α-iodo mixed acetals derived from properly substituted cyclohexenols , a process which has already been shown to permit the stereoselective and regioselective introduction of a different carbon chain at each of the termini of the allylic double bond, may be used for the construction of trans hydrindans suitable for further elaboration to steroids. In one particular instance, the process involves the formation of four new carbon-carbon bonds in a single operation.

scholarly journals Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Total Synthesis ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
Secondary Hydroxyl ◽  
Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

ChemInform Abstract: Chemistry of Organolanthanoids. Lanthanoid-Mediated C-C Bond Formation and Cleavage and C-C Double Bond Reduction.

ChemInform ◽  
1988 ◽  
Vol 19 (2) ◽  
Author(s):  
Z. HOU ◽  
Y. FUJIWARA ◽  
T. JINTOKU ◽  
N. MINE ◽  
K. YOKOO ◽  
...  
Keyword(s):  
Double Bond ◽  
Bond Formation
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