652132-97-3

Upstream product

• 1552-12-1 1,5-cis,cis-cyclooctadiene 
• 5259-72-3 cyclo-octa-1,5-diene 
• 117468-08-3 (Z)-(1S,8R)-9-oxabicyclo[6.1.0]non-4-ene 

Relevant academic research and scientific papers

Synthesis of γ-lactones from cycloocta-1,5-diene - Starting materials for natural-product synthesis

The bislactones rac-tetrahydro-2,2′-bifuranyl -5,5′-dione (rac-12) and its diastereomer meso-25 were prepared from endo-5-hydroxy-9- oxabicyclo [4.2.1]nonan-2-one (endo-10) and endo-6-hydroxy-9-oxabicyclo[3.3.1] nonan-2-one (endo-11) or exo-5-hydroxy-9-oxabicyclo[4.2.1]nonan-2-one (exo-23), respectively, under the conditions of a Baeyer-Villiger oxidation with trifluoroperacetic acid. The latter compounds were obtained by O-heterocylization of cis,cis-cycloocta-1,5-diene (1) by either reaction with peracids followed by hydrolysis and Jones oxidation or ruthenium tetraoxide oxidation, respectively. The optically active bislactone (R,R)-(-)-12 was prepared in a similar manner from (1S,5R,6R)-(+)-10 and (1R,5R,6R)-(+)-11, which, in turn, were obtained by lipase-catalyzed asymmetric acetylation of the corresponding diols meso-2 and rac-3 and subsequent Jones oxidation of the formed hydroxy esters (1S,2S,5R,6R)-(+)-4 and (1R,2R,5R,6R)-(+)-5. Since the regioisomeric hydroxy-9-oxa-bicyclo[4.2.1]- and -[3.3.1]nonan-2-ones (1S,5R,6R)-(+)-10 and (1R,5R,6R)-(+)-11 yielded the same bislactone [(R,R)-(-)-12] it is presumed that the sequence proceeds via open-chain intermediates. Applying this strategy to the enantiopure acetoxy ketones (1S,5R,6R)-(+)-8 and (1R,5R,6R)-(+)-9, followed by Kolbe electrolysis of the formed (R,R)-5-acetoxy-7-carboxyheptan-4-olide [(R,R)-27], (R,R)-5-acetoxydecan- 4-olide [(R,R)-29] was accessible in a five-step synthesis. The absolute configuration of (+)-8 was determined by X-ray analysis of the dithiepane derivative 14. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Synthesis and Expansion of Bicyclic Enol Ether: A Probable Precursor for the Synthesis of Macrolide (±)-Pyrenophorin

A convenient procedure for the synthesis and expansion of bicyclic rings has been developed for the production of probable precursors of non-racemic pyrenophorin, an antibiotic dilactone. The major highlight for this new synthetic methodology came from the use of a readily available reagent of easy manipulation, 9-oxabicyclo[3.3.1]nonane-2,6-diol, for the preparation of the bicyclic intermediate, which sequentially was subjected to oxidative cleavage with butyl nitrite resulted in an isomeric mixture, a dioximedilactone and diisoxazoledilactone.

Transannular O -heterocyclization: A useful tool for the total synthesis of Murisolin and 16,19- cis -Murisolin

Transannular O-heterocyclization is applied as a key step in a total synthesis. This highly stereoselective and metal-free transformation introduces four stereocenters in one step. It was chosen to be the pivotal step in the synthesis of Murisolin and 16,19-cis-Murisolin, two annonaceous acetogenins. The efficiency of this synthesis is further illustrated by a stereodivergent late-stage separation of both synthetic routes.

A highly efficient procedure for ruthenium tetroxide catalyzed oxidative cyclizations of 1,5-dienes

We report a highly efficient procedure for the oxidative cyclization of 1,5-dienes, which generally allows for high yields and selectivities. A solid-supported terminal oxidant and a finely tuned solvent mixture have both been identified as critical facto

Synthesis of enantiopure 9-oxabicyclononanediol derivatives by lipase-catalyzed transformations and determination of their absolute configuration

Mixtures of endo,endo-9-oxabicyclo[4.2.1]nonane-2,5-diol (meso-2) and endo,endo-9-oxabicyclo[3.3.1]nonane-2,6-diol [(±)-3] were prepared from cycloocta-1,5-diene (1) upon 09174874200 treatment with peracids by transannular O-heterocyclization and subsequent saponification of the formed diol monoesters such as (±)-4 and (±)-5. The corresponding diacetates, meso-6 and (±)-7, were formed by acetylation of either meso-2 and (±)-3 or (±)-4 and (±)-5 with acetic anhydride/pyridine. These diacetates were enantioselectively hydrolyzed by microbial enzymes such as the lipases from Candida antarctica (CAL) or Candida rugosa (CRL). The corresponding enantiomers were formed by lipase-catalyzed acetylation of the diols meso-2 and (±)-3 with vinyl acetate. The skeletal isomers can also be separated in this way because the enantiopure monoacetates 4 were formed from the meso-compounds 2 or 6, while one enantiomer of the racemic diacetate (±)-7 [or the diol (±)-3] was transformed into the enantiopure diol 3 (or the enantiopure diacetate 7, respectively) via the corresponding enantiomers of the monoacetate 5. The other enantiomer remained untouched in both cases. The lipases reacted enantioselectively to give the R isomer. Cycloocta-1,5-diene (1) was also used to synthesize 2-oxa-6-thiatricyclo[3.3.1. 13,7]decane-4,8-diol [(±)-11] in a four-step sequence. This racemic diol was also acetylated selectively (R isomer) with vinyl acetate and CRL. Reductive desulfuration of (±)-11 gave exo,exo-9-oxabicyclo[3.3.1]nonane-2,6-diol [(±)-12], which was acetylated selectively (S isomer) with CRL under the same conditions. The similarity in size and particularly in shape is responsible for the observed stereoselectivity of the lipases for the racemic endo,endo compounds (±)-3 and (±)-7 on the one hand and the exo,exo compound (±)-12 on the other hand. The absolute configuration and crystal packing of the products was determined by X-ray structural analysis. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Synthesis of (-)-xialenon A by enantioselective α-deprotonation- rearrangement of a meso-epoxide

The first total synthesis of (-)-xialenon A was achieved via enantioselective transannular desymmetrisation of a substituted cycloctene oxide using an organolithium/(-)-α-isosparteine combination. Oxidation of the resulting bicyclo[3.3.0]octanol gave an enone which underwent stereoselective conjugate allylation; subsequent α′-hydroxylation on the more hindered face of a derived enone using hypervalent iodine chemistry led to the natural product.

Selectivity of Candida rugosa lipase in simultaneous separation of skeletal isomers, desymmetrization, and kinetic racemate cleavage of 9-oxabicyclononanediols

The diols 2 and 3, available in one step from cycloocta-1,5-diene, are selectively acetylated at the (R)-centers using Candida rugosa lipase to give the corresponding enantiopure compounds. In contrast, the (S,S)-enantiomer of 11 is transformed under iden