208389-33-7

Upstream product

• 70870-92-7 (1S,2R,3R,5R)-7-oxo-3-(tetrahydropyran-2-yl)oxy-2-[3(S)-(tetrahydropyran-2-yl)oxy-E-1-octenyl]bicyclo[3.3.0]octane 
• 2548-87-0 (E)-2-Octenal 
• 208389-13-3 Acetic acid (E)-(R)-1-[(1R,2R,3aR,5S,6aS)-5-(tert-butyl-diphenyl-silanyloxy)-2-hydroxy-octahydro-pentalen-1-yl]-oct-2-enyl ester 
• 208389-08-6 (1S,3aS,5S,6aS)-5-(tert-Butyl-diphenyl-silanyloxy)-1-((E)-(R)-1-hydroxy-oct-2-enyl)-hexahydro-pentalen-2-one 
• 208389-17-7 [1S-(1α(1E,3R^*),2β,3aα,5β,6aα)]-1-(3-benzoyloxy-1-octenyl)-5-[(1,1-dimethylethyl)diphenylsilyloxy]octahydro-2-pentalenyl benzoate 
• 208389-15-5 Benzoic acid (1R,2R,3aR,5S,6aS)-1-((E)-(R)-3-acetoxy-oct-1-enyl)-5-(tert-butyl-diphenyl-silanyloxy)-octahydro-pentalen-2-yl ester 
• 208389-14-4 Benzoic acid (1R,2R,3aR,5S,6aS)-1-((E)-(R)-1-acetoxy-oct-2-enyl)-5-(tert-butyl-diphenyl-silanyloxy)-octahydro-pentalen-2-yl ester 
• 208389-16-6 Benzoic acid (1R,2R,3aR,5S,6aS)-5-(tert-butyl-diphenyl-silanyloxy)-1-((E)-(R)-3-hydroxy-oct-1-enyl)-octahydro-pentalen-2-yl ester 
• 71846-10-1 [1S-(1α(1E,3R^*),2β,3aα,5β,6aα)]-1-(3-benzoyloxy-1-octenyl)-octahydro-2,5-pentalendiol 2-benzoate 
• 71846-09-8 [3aS-(3aα,4α(1E,3R^*),5β,6aα)]-5-benzoyloxy-4-(3-benzoyloxy-1-octenyl)hexahydro-2(1H)-pentalenone 

Downstream Products

• 208389-24-6 [(3aS,4R,5R,6aS)-5-(Tetrahydro-pyran-2-yloxy)-4-[(E)-(S)-3-(tetrahydro-pyran-2-yloxy)-oct-1-enyl]-hexahydro-pentalen-(2Z)-ylidene]-acetic acid (1S,2R)-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 106402-09-9 (+)-[2-[(2R,3aS,4R,5R,6aS)-octahydro-5-hydroxy-4-[(E)-(3S,5S)-3-hydroxy-5-methyl-1-nonenyl]-2-pentalenyl]ethoxy]acetic acid 
• 208389-28-0 {(3aR,4R,5R,6aS)-5-(Tetrahydro-pyran-2-yloxy)-4-[(E)-(S)-3-(tetrahydro-pyran-2-yloxy)-oct-1-enyl]-1,3a,4,5,6,6a-hexahydro-pentalen-2-yl}-acetic acid (1S,2R)-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 208389-26-8 {(3aS,5R,6R,6aS)-5-(Tetrahydro-pyran-2-yloxy)-6-[(E)-(S)-3-(tetrahydro-pyran-2-yloxy)-oct-1-enyl]-1,3a,4,5,6,6a-hexahydro-pentalen-2-yl}-acetic acid (1S,2R)-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 

Relevant academic research and scientific papers

Asymmetric Synthesis of 3-Oxacarbacyclin and 3-Oxaisocarbacyclin by a Common Enantioselective Deprotonation Based Route

Asymmetric total syntheses of 3-oxacarbacyclin (4) and 3-oxaisocarbacyclin (5) have been achieved by a new and common route. The key step of these syntheses is an enantioselective deprotonation of the prochiral ketone 25 with lithium (R,R)-bis(phenylethyl)amide (12) in the presence of LiCl. Treatment of the thus formed enolate 26 with ClSiEt3 gave the enol ether 27 of 92% ee in 94% yield. Deprotonation of the analogous prochiral ketone 9 with 12 in the presence of LiCl followed by reaction of the enolate 13 with ClSiEt3 led to isolation of the silyl enol ether 8b of 92% ee in 95% yield. A study of the deprotonation of 9 with the chiral lithium amides 14-19 showed that 12 in combination with LiCl is the optimal base in terms of enantioselectivity and accessibility. The ω-side chain in 4 and 5 was established by a Mukaiyama reaction of 27 with the unsaturatcd aldehyde 28, leading to ketone 39 of 90% de, in combination with a stereoselective Pd-catalyzed allylic rearrangement of acetate 47 to the isomeric acetate 48 and a Mitsunobu reaction of the allylic alcohol 49. The key step in the construction of the α-side chain in 4 is a Horner-Wadsworth-Emmons reaction of ketone 7c with the 8-phenylnormenthol-containing phosphonoacetate 56 which gave ester 60 of 90% de. Ester 60 was obtained diastereomerically pure by chromatography in 72% yield from 7c. Reduction of 60 furnished the allylic alcohol 62 which was converted to 4 in a standard fashion. It is at the stage of the α,ss-unsaturated ester 60 where divergence into synthesis of 5 was made. Selective isomerization of 60 to the ss,γ-unsaturated ester 66 of 97% ie in 91% yield was accomplished by deprotonation of 60 with 12 to enolate 65 and its subsequent regioselective protonation. By a similar reaction sequence the isomeric α,ss-unsaturated ester 61 was converted to the ss,γ-unsaturated ester 69 of 97% ie in 88% yield. Reduction of 66 afforded the homoallylic alcohol 71 which was converted to 5 in a standard fashion.