Palladium-catalyzed reactions of enol ethers: Access to enals, furans, and dihydrofurans

Article abstract of DOI:10.1021/ol3028994

The palladium-catalyzed oxidation of alkyl enol ethers to enals, which employs low loadings of a palladium catalyst, is described. The mild oxidation conditions tolerate a diverse array of functional groups, while allowing the formation of di-, tri-, and tetrasubtituted olefins. The application of this methodology to intramolecular reactions of alkyl enol ethers containing pendant alcohols provides furan and 2,5-dihydrofuran products.

Full text of DOI:10.1021/ol3028994

Palladium-CatalyzedꢀReactionsꢀofꢀEnolꢀEthers:ꢀꢀAccessꢀtoꢀEnals,ꢀ
Furans,ꢀandꢀDihydrofuransꢀ
MatthewꢀG.ꢀLauer,ꢀWilliamꢀH.ꢀHenderson,ꢀAmnehꢀAwad,ꢀandꢀJamesꢀP.ꢀStambuli*ꢀ
DepartmentꢀofꢀChemistry,ꢀTheꢀOhioꢀStateꢀUniversity,ꢀ100ꢀWestꢀ18ꢀthꢀAvenue,ꢀColumbus,ꢀꢀ
Ohioꢀ43210ꢀꢀ
stambuli@chemistry.ohio-state.eduꢀ
ꢀ
Materialsꢀandꢀmethodsꢀ
S2ꢀ
Generalꢀprocedureꢀforꢀtheꢀsynthesisꢀofꢀenolꢀethersꢀ
Proceduresꢀforꢀenolꢀethersꢀ(1ꢀ-14)ꢀ
S2ꢀ
S2-S7ꢀ
Generalꢀprocedureꢀforꢀtheꢀsynthesisꢀofꢀα,β-unsaturatedꢀaldehydesꢀ
S7ꢀ
Proceduresꢀforꢀα,β-unsaturatedꢀaldehydesꢀ(1a-14a)ꢀ
S7-S12ꢀ
Generalꢀprocedureꢀforꢀtheꢀpreparationꢀofꢀ4-hydroxyꢀenolꢀethersꢀ
Proceduresꢀforꢀ4-hydroxyꢀenolꢀethersꢀ(15-19,ꢀ21-24,ꢀ27)ꢀ
Generalꢀprocedureꢀforꢀtheꢀpreparationꢀofꢀfuransꢀ
Proceduresꢀforꢀfuransꢀ(20,ꢀ21a-24a)ꢀ
S12ꢀ
S12-S16ꢀ
S16ꢀ
S16-S18ꢀ
S18ꢀ
Generalꢀprocedureꢀforꢀtheꢀpreparationꢀofꢀ2,5-dihydrofuransꢀ
Proceduresꢀforꢀ2,5-dihydrofuransꢀ(25,ꢀ26,ꢀ27a)ꢀ
Referencesꢀ
S18-S19ꢀ
S19ꢀ
1
13
Hꢀandꢀ CꢀNMRꢀspectraꢀforꢀnewꢀcompoundsꢀ
S21ꢀ
ꢀ
ꢀ
S1ꢀ
ꢀ

MaterialsꢀandꢀMethods.ꢀꢀUnlessꢀstatedꢀotherwise,ꢀpalladiumꢀcatalyzedꢀreactionsꢀwereꢀconductedꢀinꢀ4ꢀ
1
2
mLꢀborosilicateꢀglassꢀvialsꢀinꢀanꢀairꢀatmosphere.ꢀꢀAllylꢀisopropylꢀether ,ꢀallylꢀmethylꢀether ,ꢀ2-(allyloxy)-2-
3
4
5
6
methylbutane ,ꢀ allylꢀ phenylꢀ ether ,ꢀ 6-methoxyhex-5-en-1-ol ,ꢀ 5-((tert-butyldimethylsilyl)oxy)pentanal ,ꢀ
7
8
tert-butylꢀ 2-(5-oxopentyl)-1H-indole-1-carboxylate ,ꢀ andꢀ (Z)-6-(triethylsilyl)hex-5-enal ꢀ wereꢀ preparedꢀ
accordingꢀtoꢀknownꢀliteratureꢀprocedures.ꢀPalladiumꢀacetateꢀwasꢀpurifiedꢀbyꢀrecrystallizationꢀfromꢀhotꢀ
benzene.ꢀ ꢀ 1,4-Benzoquinoneꢀ wasꢀ sublimedꢀ beforeꢀ useꢀ inꢀ reactions.ꢀ ꢀ Allꢀ otherꢀ commerciallyꢀ obtainedꢀ
reagentsꢀ wereꢀ usedꢀ asꢀ received.ꢀ ꢀ Thinꢀ layerꢀ chromatographyꢀ (TLC)ꢀ wasꢀ conductedꢀ withꢀ Sorbentꢀ
4
TechnologiesꢀsilicaꢀgelꢀUV254ꢀprecoatedꢀplatesꢀ(0.25ꢀmm),ꢀandꢀvisualizedꢀusingꢀUVꢀlamps,ꢀKMnO ,ꢀandꢀ
1
13
CAMꢀ staining.ꢀ ꢀ Hꢀ andꢀ Cꢀ NMRꢀ spectraꢀ wereꢀ recordedꢀ onꢀ Brukerꢀ spectrometersꢀ andꢀ areꢀ reportedꢀ
relativeꢀtoꢀTMS.ꢀꢀIRꢀspectraꢀwereꢀrecordedꢀonꢀaꢀPerkinꢀElmerꢀ1600ꢀFT-IRꢀspectrometer.ꢀꢀHighꢀresolutionꢀ
massꢀspectraꢀwereꢀobtainedꢀfromꢀtheꢀmassꢀspectrometryꢀfacilityꢀatꢀTheꢀOhioꢀStateꢀUniversity.ꢀ
ꢀ
Generalꢀ Procedureꢀ forꢀ theꢀ Synthesisꢀ ofꢀ Enolꢀ Ethers:ꢀ Potassiumꢀ tert-butoxideꢀ (1.3ꢀ equiv)ꢀ inꢀ THFꢀ wasꢀ
slowlyꢀaddedꢀtoꢀaꢀrapidlyꢀstirringꢀsolutionꢀofꢀ(methoxymethyl)triphenylphosphoniumꢀchlorideꢀ(1.3ꢀequiv)ꢀ
inꢀTHF.ꢀTheꢀdeepꢀredꢀsolutionꢀwasꢀallowedꢀtoꢀstirꢀatꢀ23ꢀ°Cꢀforꢀ45ꢀminꢀbeforeꢀslowlyꢀaddingꢀaꢀsolutionꢀofꢀ
theꢀaldehydeꢀ(1ꢀequiv)ꢀinꢀTHF.ꢀTheꢀsolutionꢀturnedꢀfromꢀdeepꢀredꢀtoꢀorangeꢀandꢀwasꢀallowedꢀtoꢀstirꢀforꢀ
anꢀadditionalꢀ4ꢀh.ꢀTheꢀsolventꢀwasꢀreducedꢀunderꢀvacuumꢀandꢀdilutedꢀwithꢀhexanes.ꢀTheꢀorganicꢀlayerꢀ
4
wasꢀwashedꢀwithꢀwaterꢀandꢀbrineꢀfollowedꢀbyꢀdryingꢀtheꢀorganicꢀlayerꢀoverꢀMgSO .ꢀTheꢀorganicꢀlayerꢀ
wasꢀ removedꢀ underꢀ vacuumꢀ andꢀ theꢀ resultingꢀ oilꢀ purifiedꢀ byꢀ Kugelrohrꢀ distillationꢀ underꢀ reducedꢀ
pressureꢀorꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgel.ꢀ
ꢀ
(
4-(Methoxymethylene)cyclohexyl)benzeneꢀ (1):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ 4-
phenylcyclohexanoneꢀ(707ꢀmg,ꢀ4.05ꢀmmol)ꢀandꢀ(2-methoxymethyl)triphenylphosphoniumꢀchlorideꢀ(1.90ꢀ
g,ꢀ5.54ꢀmmol,ꢀ1.35ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(614ꢀmg,ꢀ5.47ꢀmmol,ꢀ1.35ꢀequiv).ꢀTheꢀcrudeꢀoilꢀ
wasꢀ purifiedꢀ byꢀ Kugelrohrꢀ distillationꢀ underꢀ reducedꢀ pressureꢀ toꢀ giveꢀ (4-
(
methoxymethylene)cyclohexyl)benzeneꢀ(791ꢀmg,ꢀ3.91ꢀmmol,ꢀ96%)ꢀaꢀclear,ꢀcolorlessꢀoil.ꢀꢀSpectralꢀdataꢀ
9
ꢀ
ofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀvalues.
ꢀ
1
-Methoxytridec-1-eneꢀ(2):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ1-dodecanalꢀ(1.7ꢀmL,ꢀ7.85ꢀ
mmol)ꢀ andꢀ (2-methoxymethyl)triphenylphosphoniumꢀ chlorideꢀ (2.69ꢀ g,ꢀ 7.85ꢀ mmol,ꢀ 1.02ꢀ equiv)ꢀ withꢀ
potassiumꢀ tert-butoxideꢀ (0.99ꢀ g,ꢀ 8.88ꢀ mmol,ꢀ 1.16ꢀ equiv).ꢀ Theꢀ resultingꢀ oilꢀ wasꢀ purifiedꢀ byꢀ Kugelrohrꢀ
distillationꢀunderꢀreducedꢀpressureꢀtoꢀgiveꢀ1-methoxytridec-1-eneꢀ(1.35ꢀg,ꢀ7.66ꢀmmol,ꢀ83%)ꢀasꢀaꢀclear,ꢀ
S2ꢀ
ꢀ

colorlessꢀoil.ꢀTheꢀproductꢀwasꢀisolatedꢀasꢀaꢀ1.6:1ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀSpectralꢀdataꢀofꢀtheꢀproductꢀ
1
0ꢀ
matchedꢀreportedꢀliteratureꢀvalues.
ꢀ
(
4-methoxybut-3-en-1-yl)benzeneꢀ (3):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ 3-
phenylpropanalꢀ (2.94ꢀ mL,ꢀ 21.9ꢀ mmol)ꢀ andꢀ (2-methoxymethyl)triphenylphosphoniumꢀ chlorideꢀ (10.2ꢀ g,ꢀ
9.7ꢀmmol,ꢀ1.35ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(3.33ꢀg,ꢀ29.7ꢀmmol,ꢀ1.35ꢀequiv).ꢀTheꢀcrudeꢀoilꢀwasꢀ
2
purifiedꢀbyꢀKugelrohrꢀdistillationꢀunderꢀreducedꢀpressureꢀtoꢀgiveꢀ(4-methoxybut-3-en-1-yl)benzeneꢀ(2.96ꢀ
g,ꢀ18.2ꢀmmol,ꢀ83%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀSpectralꢀdataꢀofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀ
1
0ꢀ
values.
ꢀ
tert-Butyl((6-methoxyhex-5-en-1-yl)oxy)dimethylsilaneꢀ(4):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀ
6
usingꢀ
5-((tert-butyldimethylsilyl)oxy)pentanal ꢀ
(5.45ꢀ
g,ꢀ
25.2ꢀ
mmol)ꢀ
andꢀ
(2-
methoxymethyl)triphenylphosphoniumꢀ chlorideꢀ (11.2ꢀ g,ꢀ 32.7ꢀ mmol,ꢀ 1.3ꢀ equiv)ꢀ withꢀ potassiumꢀ tert-
butoxideꢀ(3.68ꢀg,ꢀ32.8ꢀmmol,ꢀ1.3ꢀequiv).ꢀtert-Butyl((6-methoxyhex-5-en-1-yl)oxy)dimethylsilaneꢀ(4.41ꢀg,ꢀ
1
8.1ꢀmmol,ꢀ72%)ꢀwasꢀisolatedꢀbyꢀKugelrohrꢀdistillationꢀtoꢀgiveꢀaꢀclear,ꢀcolorlessꢀoil.ꢀTheꢀproductꢀwasꢀ
-
1
1
isolatedꢀasꢀaꢀ1.7:1ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2929,ꢀ2856,ꢀ1654,ꢀ1462,ꢀ1255,ꢀ1209,ꢀ1101;ꢀ Hꢀ
NMRꢀ(CDCl ,ꢀ400ꢀMHz):ꢀδꢀ6.27ꢀ(d,ꢀJꢀ=ꢀ12.4ꢀHz,ꢀ1H),ꢀ5.86ꢀ(d,ꢀJꢀ=ꢀ6.4ꢀHz,ꢀ0.6H),ꢀ4.72ꢀ(dt,ꢀJꢀ=ꢀ12.4,ꢀ7.2Hz,ꢀ1H),ꢀ
.33ꢀ(q,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ0.6H),ꢀ3.60ꢀ(t,ꢀJꢀ=ꢀ6.4ꢀHz,ꢀ3.2H),ꢀ3.57ꢀ(s,ꢀ1.7H),ꢀ3.49ꢀ(s,ꢀ3H),ꢀ2.07ꢀ(qd,ꢀJꢀ=ꢀ7.6,ꢀ1.2ꢀHz,ꢀ
3
4
1
1
3
.2H),ꢀ1.93ꢀ(q,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ2H),ꢀ1.57-1.49ꢀ(m,ꢀ3.2H),ꢀ1.41-1.34ꢀ(m,ꢀ3.2H),ꢀ0.90ꢀ(s,ꢀ14.4H),ꢀ0.46ꢀ(s,ꢀ9.5H);ꢀ Cꢀ
NMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ147.3,ꢀ146.3,ꢀ107.1,ꢀ103.2,ꢀ63.4,ꢀ63.3,ꢀ59.6,ꢀ56.1,ꢀ32.7,ꢀ32.4,ꢀ27.7,ꢀ27.2,ꢀ26.2,ꢀ
+
2
3.8,ꢀ18.6,ꢀ-5.1;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C13
H
28
O
2
Siꢀ+ꢀNa] ꢀcalcdꢀ267.1751,ꢀfoundꢀ267.1761.ꢀ
ꢀ
5
6
-methoxyhex-5-en-1-ylꢀ acetateꢀ (5):ꢀ Toꢀ aꢀ stirringꢀ solutionꢀ ofꢀ 6-methoxyhex-5-en-1-ol ꢀ (0.825ꢀ g,ꢀ 6.34ꢀ
Cl ꢀ(11ꢀmL)ꢀwasꢀaddedꢀaceticꢀanhydrideꢀ(1.20ꢀ
mmol)ꢀandꢀpyridineꢀ(1.60ꢀmL,ꢀ19.8ꢀmmol,ꢀ3ꢀequiv)ꢀinꢀCH
2
2
mL,ꢀ12.7ꢀmmol,ꢀ2ꢀequiv)ꢀandꢀ4-(dimethylamino)pyridineꢀ(79.5ꢀmg,ꢀ0.651ꢀmmol,ꢀ0.1ꢀequiv)ꢀatꢀ0ꢀ°C.ꢀTheꢀ
reactionꢀ wasꢀ allowedꢀ toꢀ stirꢀ forꢀ 30ꢀ minꢀ atꢀ 0ꢀ °Cꢀ andꢀ anꢀ additionalꢀ 15ꢀ hꢀ atꢀ 23ꢀ °C.ꢀ Theꢀ mixtureꢀ wasꢀ
quenchedꢀ withꢀ saturatedꢀ aqueousꢀ NaHCO
3
ꢀ (100ꢀ mL)ꢀ andꢀ extractedꢀ withꢀ CH
2 2
Cl ꢀ (3ꢀ xꢀ 100ꢀ mL).ꢀ Theꢀ
combinedꢀorganicꢀlayersꢀwereꢀdriedꢀoverꢀNa
2
SO ,ꢀfiltered,ꢀandꢀfreedꢀofꢀsolventꢀunderꢀreducedꢀpressureꢀ
4
toꢀaffordꢀaꢀyellowꢀoil,ꢀwhichꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(15%ꢀEtOAc/hexanes)ꢀtoꢀ
giveꢀ6-methoxyhex-5-en-1-ylꢀacetateꢀ(0.994ꢀg,ꢀ5.77ꢀmmol,ꢀ91%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀꢀTheꢀproductꢀwasꢀ
-
1
1
isolatedꢀasꢀaꢀ2:1ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀFTIR(film,ꢀcm ):ꢀ2940,ꢀ1713,ꢀ1434,ꢀ1402,ꢀ1208,ꢀ1142;ꢀ HꢀNMRꢀ
CDCl ,ꢀ400ꢀMHz):ꢀδꢀ6.29ꢀ(d,ꢀJꢀ=ꢀ12.4ꢀHz,ꢀ0.5H),ꢀ5.89ꢀ(dt,ꢀJꢀ=ꢀ6.0,ꢀ1.2ꢀHz,ꢀ0.5H),ꢀ4.70ꢀ(dt,ꢀJꢀ=ꢀ12.4,ꢀ7.2ꢀHz,ꢀ
H),ꢀ4.33-4.29ꢀ(m,ꢀ0.5H),ꢀ4.06ꢀ(t,ꢀJꢀ=ꢀ6.8ꢀHz,ꢀ3.1H),ꢀ3.57ꢀ(s,ꢀ1.4H),ꢀ3.50ꢀ(s,ꢀ3H),ꢀ2.12-2.06ꢀ(m,ꢀ5.6ꢀH),ꢀ1.99-
(
3
1
1
1
3
.93ꢀ(m,ꢀ2H),ꢀ1.67-1.60ꢀ(m,ꢀ3.1H),ꢀ1.44-1.37ꢀ(m,ꢀ3.1H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ171.3,ꢀ147.6,ꢀ146.7,ꢀ
S3ꢀ
ꢀ

1
+
06.4,ꢀ102.6,ꢀ64.7,ꢀ64.6,ꢀ59.6,ꢀ56.1,ꢀ28.3,ꢀ28.1,ꢀ27.5,ꢀ27.2,ꢀ26.2,ꢀ23.6,ꢀ21.2;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C
9
H
16
O
3
ꢀ
+
ꢀNa] ꢀcalcdꢀ195.0992,ꢀfoundꢀ195.0996.ꢀ
ꢀ
Triethyl((1Z)-7-methoxyhepta-1,6-dien-1-yl)silaneꢀ(6):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ
8
(
Z)-6-(triethylsilyl)hex-5-enal ꢀ (2.00ꢀ g,ꢀ 11.5ꢀ mmol)ꢀ andꢀ (2-methoxymethyl)triphenylphosphoniumꢀ
chlorideꢀ(4.62ꢀg,ꢀ13.7ꢀmmol,ꢀ1.5ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(1.54ꢀg,ꢀ13.7ꢀmmol,ꢀ1.5ꢀequiv).ꢀTheꢀ
resultingꢀ oilꢀ wasꢀ purifiedꢀ byꢀ flashꢀ chromatographyꢀ onꢀ silicaꢀ gelꢀ (hexanes)ꢀ toꢀ giveꢀ triethyl((1Z)-7-
methoxyhepta-1,6-ꢀdien-1-yl)silaneꢀ(1.15ꢀg,ꢀ4.78ꢀmmol,ꢀ51%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀTheꢀproductꢀwasꢀ
-
1
1
isolatedꢀasꢀaꢀ2:1ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2952,ꢀ2873,ꢀ1728,ꢀ1605,ꢀ1461,ꢀ1016;ꢀ HꢀNMRꢀ
CDCl ,ꢀ400ꢀMHz):ꢀδꢀ6.36ꢀ(m,ꢀ3.4H),ꢀ6.29ꢀ(d,ꢀJꢀ=ꢀ12.4ꢀHz,ꢀ2H),ꢀ5.88ꢀ(dd,ꢀJꢀ=ꢀ6.4,ꢀ1.2ꢀHz,ꢀ1H),ꢀ5.43-5.37ꢀ(m,ꢀ
.4H),ꢀ4.72ꢀ(dt,ꢀJꢀ=ꢀ12.4,ꢀ7.2ꢀHz,ꢀ2H),ꢀ4.34-4.30ꢀ(m,ꢀ1H),ꢀ3.57ꢀ(s,ꢀ3H),ꢀ3.50ꢀ(s,ꢀ6H),ꢀ2.14-2.07ꢀ(m,ꢀ9.3H),ꢀ1.94ꢀ
(
3
3
1
3
(
q,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ4H),ꢀ1.46-1.39ꢀ(m,ꢀ6.6H),ꢀ0.94ꢀ(s,ꢀ32H),ꢀ0.61ꢀ(q,ꢀJꢀ=ꢀ8.0ꢀHz,ꢀ21H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀ
δꢀ150.4,ꢀ150.1,ꢀ147.5,ꢀ146.5,ꢀ125.5,ꢀ125.3,ꢀ106.8,ꢀ102.9,ꢀ59.6,ꢀ56.0,ꢀ33.9,ꢀ33.7,ꢀ31.1,ꢀ30.2,ꢀ27.7,ꢀ23.9,ꢀ7.7,ꢀ
+
4
.9;ꢀꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C14H28OSiꢀ+ꢀNa] ꢀcalcdꢀ263.1802,ꢀfoundꢀ263.1815.ꢀ
ꢀ
8
-(methoxymethylene)-1,4-dioxaspiro[4.5]decaneꢀ(7):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ
1
,4-dioxaspiro[4.5]decan-8-oneꢀ (2.04ꢀ g,ꢀ 13.0ꢀ mmol)ꢀ andꢀ (2-ꢀ methoxymethyl)triphenylphosphoniumꢀ
chlorideꢀ(5.81ꢀg,ꢀ16.9ꢀmmol,ꢀ1.30ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(1.90ꢀg,ꢀ16.9ꢀmmol,ꢀ1.30ꢀequiv).ꢀ
Theꢀ resultingꢀ oilꢀ wasꢀ purifiedꢀ byꢀ flashꢀ chromatographyꢀ onꢀ silicaꢀ gelꢀ (10%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ 8-
(
(
methoxymethylene)-1,4-dioxaspiro[4.5]decaneꢀ(1.65ꢀg,ꢀ8.96ꢀmmol,ꢀ69%)ꢀasꢀaꢀclearꢀcolorlessꢀoil.ꢀꢀFTIRꢀ
-
1
1
3
film,ꢀcm ):ꢀ2952,ꢀ2885,ꢀ1718,ꢀ1127,ꢀ1099;ꢀ HꢀNMRꢀ(CDCl ,ꢀ400ꢀMHz):ꢀδꢀ5.78ꢀ(s,ꢀ1H),ꢀ3.94ꢀ(s,ꢀ4H),ꢀ3.53ꢀ(s,ꢀ
1
3
3
1
H),ꢀ2.31ꢀ(t,ꢀJꢀ=ꢀ6.8ꢀHz,ꢀ2H),ꢀ2.09ꢀ(t,ꢀJꢀ=ꢀ6.8ꢀHz,ꢀ4H),ꢀ1.64-1.59ꢀ(m,ꢀ4H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ139.4,ꢀ
+
14.9,ꢀ108.9,ꢀ64.0,ꢀ58.9,ꢀ35.9,ꢀ34.6,ꢀ27.1,ꢀ21.9.ꢀꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C11 ꢀ+ꢀNa] ꢀcalcdꢀ207.0992,ꢀ
16 3
H O
foundꢀ2.0993.ꢀ
ꢀ
1
-(tert-butyl)-4-(methoxymethylene)cyclohexaneꢀ(8):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ
-(tert-butyl)cyclohexanoneꢀ(2.07ꢀg,ꢀ13.4ꢀmmol)ꢀandꢀ(2-methoxymethyl)triphenylphosphoniumꢀchlorideꢀ
4
(
5.97ꢀg,ꢀ17.4ꢀmmol,ꢀ1.3ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(1.95ꢀg,ꢀ17.4ꢀmmol,ꢀ1.3ꢀequiv).ꢀTheꢀresultingꢀ
oilꢀ wasꢀ purifiedꢀ byꢀ Kugelrohrꢀ distillationꢀ underꢀ reducedꢀ pressureꢀ toꢀ giveꢀ 1-(tert-butyl)-4-
methoxymethylene)cyclohexaneꢀ(2.11ꢀg,ꢀ11.6ꢀmmol,ꢀ87%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀꢀSpectralꢀdataꢀofꢀtheꢀ
(
1
1
productꢀmatchedꢀreportedꢀliteratureꢀvalues. ꢀ
S4ꢀ
ꢀ

ꢀ
5
2
-(6-methoxyhex-5-en-1-yl)isoindoline-1,3-dioneꢀ(9):ꢀToꢀaꢀstirringꢀsolutionꢀofꢀ6-methoxyhex-5-en-1-ol ꢀ
(
1.30ꢀg,ꢀ9.98ꢀmmol),ꢀphthalimideꢀ(1.62ꢀg,ꢀ11.0ꢀmmol),ꢀandꢀPPh3ꢀ(2.89ꢀg,ꢀ11.0ꢀmmol)ꢀinꢀTHFꢀ(20ꢀmL)ꢀwasꢀ
addedꢀdiisopropylꢀazodicarboxylateꢀ(2.25ꢀg,ꢀ11.1ꢀmmol)ꢀoverꢀ40ꢀminꢀatꢀ23ꢀ°C.ꢀTheꢀreactionꢀwasꢀallowedꢀ
toꢀstirꢀforꢀ48ꢀh.ꢀTheꢀreactionꢀwasꢀreducedꢀunderꢀvacuumꢀandꢀdiethylꢀetherꢀaddedꢀbeforeꢀfilteringꢀoverꢀ
Celite.ꢀ Theꢀ filtrateꢀ wasꢀ thenꢀ reducedꢀ underꢀ vacuumꢀ andꢀ theꢀ yellow-orangeꢀ oilꢀ purifiedꢀ byꢀ flashꢀ
chromatographyꢀ onꢀ silicaꢀ gelꢀ (20%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ 2-(6-methoxyhex-5-en-1-yl)isoindoline-1,3-
dioneꢀ(2.18ꢀg,ꢀ8.41ꢀmmol,ꢀ84%)ꢀasꢀaꢀyellowꢀoil.ꢀTheꢀproductꢀwasꢀisolatedꢀasꢀaꢀ1.8:1ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀ
-
1
1
FTIRꢀ(film,ꢀcm ):ꢀ3032,ꢀ2936,ꢀ2856,ꢀ1770,ꢀ1713,ꢀ1395,ꢀ1208,ꢀ1106;ꢀ HꢀNMRꢀ(CDCl
m,ꢀ5.7H),ꢀ7.70-7.68ꢀ(m,ꢀ5.7H),ꢀ6.26ꢀ(d,ꢀJꢀ=ꢀ12.4ꢀHz,ꢀ1.8H),ꢀ5.85ꢀ(d,ꢀJꢀ=ꢀ6.0ꢀHz,ꢀ1H),ꢀ4.67ꢀ(m,ꢀ1.8H),ꢀ4.29ꢀ(q,ꢀ
Jꢀ=ꢀ7.2ꢀHz,ꢀ1H),ꢀ3.67ꢀ(t,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ5.9H),ꢀ3.54ꢀ(s,ꢀ3H),ꢀ3.47ꢀ(s,ꢀ5.4H)ꢀ2.08ꢀ(q,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ2H),ꢀ1.95ꢀ(q,ꢀJꢀ=ꢀ7.2ꢀ
3
,ꢀ400ꢀMHz):ꢀδꢀ7.83-7.80ꢀ
(
1
3
Hz,ꢀ3.8H),ꢀ1.72-1.63ꢀ(m,ꢀ5.8H),ꢀ1.42-1.34ꢀ(m,ꢀ5.8H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ168.3,ꢀ147.3,ꢀ146.4,ꢀ
1
33.8,ꢀ133.7,ꢀ123.0ꢀ(2C),ꢀ106.0,ꢀ102.2,ꢀ59.4,ꢀ55.8,ꢀ37.9,ꢀ37.8,ꢀ28.0,ꢀ27.8,ꢀ27.1,ꢀ26.9,ꢀ23.2;ꢀHRMSꢀ(ES)ꢀcalcdꢀ
+
3
forꢀ[C15H17NO ꢀ+ꢀNa] ꢀcalcdꢀ282.1101,ꢀfoundꢀ282.1088.ꢀ
ꢀ
5
1
-(6-methoxyhex-5-en-1-yl)pyrrolidine-2,5-dioneꢀ(10):ꢀToꢀaꢀstirringꢀsolutionꢀofꢀ6-methoxyhex-5-en-1-ol ꢀ
(
497ꢀmg,ꢀ3.82ꢀmmol),ꢀsuccinimideꢀ(421ꢀmg,ꢀ4.25ꢀmmol,ꢀ1.1ꢀequiv),ꢀandꢀPPh
3
ꢀ(1.10ꢀg,ꢀ4.20ꢀmmol,ꢀ1.1ꢀ
equiv)ꢀinꢀTHFꢀ(6.5ꢀmL)ꢀwasꢀaddedꢀdiisopropylꢀazodicarboxylateꢀ(0.90ꢀmL,ꢀ4.6ꢀmmol,ꢀ1.2ꢀequiv)ꢀoverꢀ40ꢀ
minꢀatꢀ23ꢀ°C.ꢀTheꢀreactionꢀwasꢀallowedꢀtoꢀstirꢀforꢀ5ꢀh.ꢀTheꢀreactionꢀwasꢀreducedꢀunderꢀvacuumꢀandꢀtheꢀ
yellow-orangeꢀ oilꢀ purifiedꢀ byꢀ flashꢀ chromatographyꢀ onꢀ silicaꢀ gelꢀ (40%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ 1-(6-
methoxyhex-5-en-1-yl)pyrrolidine-2,5-dioneꢀ (753ꢀ mg,ꢀ 3.56ꢀ mmol,ꢀ 93%)ꢀ asꢀ aꢀ yellowꢀ oil.ꢀ ꢀ Isolatedꢀ asꢀ aꢀ
-
1
1
2
.6:1ꢀ(E:Z)ꢀmixtureꢀofꢀisomers.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2936,ꢀ2856,ꢀ1740,ꢀ1654,ꢀ1241,ꢀ1038;ꢀ HꢀNMRꢀ(CDCl
MHz):ꢀδꢀ6.27ꢀ(dt,ꢀJꢀ=ꢀ12.4ꢀHz,ꢀ1H),ꢀ5.87ꢀ(dt,ꢀJꢀ=ꢀ6.0,ꢀ1.6ꢀHz,ꢀ0.4ꢀH),ꢀ4.68ꢀ(dt,ꢀJꢀ=ꢀ12.8,ꢀ7.2ꢀHz,ꢀ1H),ꢀ4.29ꢀ(dt,ꢀJꢀ
ꢀ6.0Hz,ꢀ0.4H),ꢀ3.57ꢀ(s,ꢀ1.2ꢀH),ꢀ3.50ꢀ(t,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ2.8H),ꢀ3.49ꢀ(s,ꢀ3ꢀH),ꢀ2.70ꢀ(s,ꢀ4H),ꢀ2.69ꢀ(s,ꢀ1.6H),ꢀ2.07ꢀ(dq,ꢀ
3
,ꢀ400ꢀ
=
1
3
Jꢀ=ꢀ7.4,ꢀ1.2ꢀHz,ꢀ0.8H),ꢀ1.94ꢀ(dq,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ0.8ꢀHz,ꢀ2H),ꢀ1.62-1.53ꢀ(m,ꢀ2.8H),ꢀ1.38-130ꢀ(m,ꢀ2.8H);ꢀ CꢀNMRꢀ
(
(
CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ177.4,ꢀ147.6,ꢀ146.7,ꢀ106.2,ꢀ102.5,ꢀ59.7,ꢀ56.1,ꢀ39.0,ꢀ38.9,ꢀ28.4,ꢀ28.1,ꢀ27.4ꢀ(2ꢀC),ꢀ27.2ꢀ
+
2ꢀC),ꢀ23.5;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C11
H
17NO
3
ꢀ+ꢀNa] ꢀcalcdꢀ234.1101,ꢀfoundꢀ234.1108.ꢀ
ꢀ
-(methoxymethylene)-6,7,8,9-tetrahydro-5H-benzo[7]annuleneꢀ (11):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ
5
wasꢀ
followedꢀ
usingꢀ
1-benzosuberoneꢀ
(3.2ꢀ
mL,ꢀ
21.4ꢀ
mmol)ꢀ
andꢀ
(2-ꢀ
S5ꢀ
ꢀ

methoxymethyl)triphenylphosphoniumꢀ chlorideꢀ (8.98ꢀ g,ꢀ 26.2ꢀ mmol,ꢀ 1.22ꢀ equiv)ꢀ withꢀ potassiumꢀ tert-
butoxideꢀ(2.93ꢀg,ꢀ26.1ꢀmmol,ꢀ1.22ꢀequiv).ꢀTheꢀresultingꢀoilꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀ
gelꢀ(hexanes)ꢀtoꢀgiveꢀ(3.04ꢀg,ꢀ16.1ꢀmmol,ꢀ75%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀTheꢀproductꢀwasꢀisolatedꢀasꢀaꢀ
-
1
1
1
:1.8ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3057,ꢀ3012,ꢀ2927,ꢀ2849,ꢀ1658,ꢀ1443,ꢀ1221,ꢀ1130;ꢀ HꢀNMRꢀ
CDCl ,ꢀ400ꢀMHz):ꢀδꢀ7.26-7.24ꢀ(m,ꢀ1H),ꢀ7.15-7.06ꢀ(m,ꢀ11H),ꢀ6.06ꢀ(s,ꢀ1H),ꢀ6.02ꢀ(s,ꢀ1.9H),ꢀ3.66ꢀ(s,ꢀ6H),ꢀ3.54ꢀ
s,ꢀ3H),ꢀ2.74-2.71ꢀ(m,ꢀ6H),ꢀ2.38ꢀ(s,ꢀ4H),ꢀ2.13-2.10ꢀ(m,ꢀ2H),ꢀ1.80-1.64ꢀ(m,ꢀ12H);ꢀ CꢀNMRꢀ(CDCl
(
(
3
1
3
3
,ꢀ100ꢀMHz):ꢀ
δꢀ144.7,ꢀ143.2,ꢀ141.8ꢀ(2),ꢀ141.4,ꢀ139.5,ꢀ130.3,ꢀ129.6,ꢀ129.2,ꢀ128.2,ꢀ126.8ꢀ(2ꢀC),ꢀ126.3,ꢀ125.8,ꢀ122.1,ꢀ120.4,ꢀ
+
6
0.0,ꢀ37.2,ꢀ35.8ꢀ(2ꢀC),ꢀ32.8,ꢀ28.5,ꢀ27.9,ꢀ27.8,ꢀ27.0;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C13
H16Oꢀ+ꢀNa] ꢀcalcdꢀ211.1093,ꢀ
foundꢀ211.1088.ꢀ
ꢀ
(
1-cyclohexyl-2-methoxyvinyl)benzeneꢀ (12):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ
cyclohexylꢀ phenylꢀ ketoneꢀ (1.96ꢀ g,ꢀ 10.4ꢀ mmol)ꢀ andꢀ (2-methoxymethyl)triphenylphosphoniumꢀ chlorideꢀ
4.63ꢀg,ꢀ13.5ꢀmmol,ꢀ1.3ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(1.52ꢀg,ꢀ13.5ꢀmmol,ꢀ1.3ꢀequiv).ꢀTheꢀresultingꢀ
(
oilꢀ wasꢀ purifiedꢀ byꢀ flashꢀ chromatographyꢀ onꢀ silicaꢀ gelꢀ (hexanes)ꢀ toꢀ giveꢀ (Z)-(1-cyclohexyl-2-
methoxyvinyl)benzeneꢀ(0.70ꢀg,ꢀ3.25ꢀmmol,ꢀ31%)ꢀandꢀ(E)-(1-cyclohexyl-2-methoxyvinyl)benzeneꢀ(1.30ꢀg,ꢀ
-
1
6
3
7
1
1
.01ꢀ mmol,ꢀ 58%)ꢀ asꢀ clear,ꢀ colorlessꢀ oils.ꢀ ꢀ (Z)-(1-cyclohexyl-2-methoxyvinyl)benzene:ꢀ FTIRꢀ (film,ꢀ cm ):ꢀ
1
027,ꢀ2923,ꢀ2850,ꢀ1650,ꢀ1493,ꢀ1447,ꢀ1219,ꢀ1130,ꢀ1072;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.28-7.24ꢀ(m,ꢀ2H),ꢀ
.22-ꢀ7.17ꢀ(m,ꢀ3H),ꢀ5.91ꢀ(s,ꢀ1H),ꢀ3.63ꢀ(s,ꢀ3H),ꢀ2.64ꢀ(tt,ꢀJꢀ=ꢀ12.4,ꢀ3.2ꢀHz,ꢀ1H),ꢀ1.75-1.61ꢀ(m,ꢀ5H),ꢀ1.45ꢀ(qd,ꢀJꢀ=ꢀ
1
3
3.6,ꢀ5.6ꢀHz,ꢀ2H),ꢀ1.30ꢀ(qt,ꢀJꢀ=ꢀ12.8,ꢀ3.2ꢀHz,ꢀ2H),ꢀ1.18-1.06ꢀ(m,ꢀ1H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ145.2,ꢀ
40.5,ꢀ 128.9,ꢀ 127.9,ꢀ 126.3,ꢀ 126.0,ꢀ 59.9,ꢀ 39.5,ꢀ 31.7,ꢀ 27.2,ꢀ 26.4.ꢀ ꢀ (E)-(1-cyclohexyl-2-
-
1
1
methoxyvinyl)benzene:ꢀFTIRꢀ(film,ꢀcm ):ꢀ3053,ꢀ3018,ꢀ2925,ꢀ2850,ꢀ1657,ꢀ1448,ꢀ1249,ꢀ1204,ꢀ1147;ꢀ HꢀNMRꢀ
CDCl ,ꢀ400ꢀMHz):ꢀδꢀ7.32-7.24ꢀ(m,ꢀ4H),ꢀ7.21-7.17ꢀ(1H),ꢀ5.95ꢀ(d,ꢀJꢀ=ꢀ1.1ꢀHz,ꢀ1H),ꢀ3.55ꢀ(s,ꢀ3H),ꢀ2.24-2.17ꢀ(m,ꢀ
H),ꢀ1.79-1.71ꢀ(m,ꢀ4H),ꢀ1.68-1.63ꢀ(m,ꢀ1H),ꢀ1.32-1.21ꢀ(m,ꢀ2H),ꢀ1.17-1.06ꢀ(m,ꢀ3H);ꢀ CꢀNMRꢀ(CDCl
MHz):ꢀδꢀ143.0,ꢀ138.6,ꢀ129.0,ꢀ127.9,ꢀ126.2,ꢀ124.2,ꢀ59.8,ꢀ41.7,ꢀ33.2,ꢀ27.0,ꢀ26.5;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ
(
3
1
3
1
3
,ꢀ100ꢀ
+
15
[C H20Oꢀ+ꢀNa] ꢀcalcdꢀ239.1406,ꢀfoundꢀ239.1410.ꢀ
ꢀ
1
-methoxy-4,8-dimethylnona-1,7-dieneꢀ (13):ꢀ ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ (±)-
citronellalꢀ(1.80ꢀmL,ꢀ1.54ꢀg,ꢀ10.0ꢀmmol)ꢀandꢀ(2-methoxymethyl)triphenylphosphoniumꢀchlorideꢀ(4.56ꢀg,ꢀ
3.3ꢀmmol,ꢀ1.3ꢀequiv)ꢀwithꢀpotassiumꢀtert-butoxideꢀ(1.46ꢀg,ꢀ13.0ꢀmmol,ꢀ1.3ꢀequiv).ꢀTheꢀresultingꢀoilꢀwasꢀ
purifiedꢀbyꢀKugelrohrꢀdistillationꢀunderꢀreducedꢀpressureꢀtoꢀgiveꢀ1-methoxy-4,8-dimethylnona-1,7-dieneꢀ
1
(
1.64ꢀ g,ꢀ 9.04ꢀ mmol,ꢀ 90%)ꢀ asꢀ aꢀ clear,ꢀ colorlessꢀ oil.ꢀ ꢀ Theꢀ productꢀ wasꢀ isolatedꢀ asꢀ aꢀ 1.2:1ꢀ (E:Z)ꢀ mixtureꢀ
1
2ꢀ
isomers.ꢀꢀSpectralꢀdataꢀofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀvalues.
S6ꢀ
ꢀ

ꢀ
tert-butylꢀ2-(6-methoxyhex-5-en-1-yl)-1H-indole-1-carboxylateꢀ(14):ꢀꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀ
7
followedꢀ usingꢀ tert-butylꢀ 2-(5-oxopentyl)-1H-indole-1-carboxylate ꢀ (1.03ꢀ g,ꢀ 3.42ꢀ mmol)ꢀ andꢀ (2-ꢀ
methoxymethyl)triphenylphosphoniumꢀ chlorideꢀ (3.51ꢀ g,ꢀ 10.2ꢀ mmol,ꢀ 3.0ꢀ equiv)ꢀ withꢀ potassiumꢀ tert-
butoxideꢀ(1.15ꢀg,ꢀ10.2ꢀmmol,ꢀ3.0ꢀequiv).ꢀTheꢀresultingꢀoilꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀ
2 2
gelꢀ(20-40%ꢀCH Cl /hexanes)ꢀtoꢀgiveꢀ(0.7232ꢀg,ꢀ2.20ꢀmmol,ꢀ64%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀTheꢀproductꢀwasꢀ
-
1
isolatedꢀasꢀaꢀ1.2:1ꢀ(E:Z)ꢀmixtureꢀisomers.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3030,ꢀ2977,ꢀ2932,ꢀ2855,ꢀ1732,ꢀ1654,ꢀ1567,ꢀ
1
1
2
455,ꢀ1329,ꢀ1116,ꢀ747;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ8.11-8.08ꢀ(m,ꢀ1H),ꢀ7.45-7.42ꢀ(m,ꢀ1H),ꢀ7.24-7.15ꢀ(m,ꢀ
H),ꢀ6.34ꢀ(m,ꢀ1H),ꢀ6.29ꢀ(dt,ꢀJꢀ=ꢀ12.6,ꢀ1.0ꢀHz,ꢀ0.55H),ꢀ5.87ꢀ(dt,ꢀJꢀ=ꢀ6.2,ꢀ1.4ꢀHz,ꢀ0.45H),ꢀ4.73ꢀ(dt,ꢀJꢀ=ꢀ12.6,ꢀ7.3ꢀ
Hz,ꢀ0.55H),ꢀ4.34ꢀ(dt,ꢀJꢀ=ꢀ7.3,ꢀ6.2ꢀHz,ꢀ0.45H),ꢀ3.57ꢀ(s,ꢀ1.35H),ꢀ3.49ꢀ(s,ꢀ1.65H),ꢀ2.99ꢀ(m,ꢀ2H),ꢀ2.13ꢀ(m,ꢀ1H),ꢀ
1
3
1
1
1
+
.98ꢀ(m,ꢀ1H),ꢀ1.76-1.68ꢀ(m,ꢀ11H),ꢀ1.52-1.43ꢀ(m,ꢀ2H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ150.6,ꢀ147.2,ꢀ146.3,ꢀ
42.5,ꢀ142.4,ꢀ136.7ꢀ(2ꢀC),ꢀ129.4ꢀ(2ꢀC),ꢀ123.2,ꢀ123.1,ꢀ122.6,ꢀ122.5,ꢀ119.6ꢀ(2ꢀC),ꢀ115.6,ꢀ115.5,ꢀ107.1,ꢀ107.0,ꢀ
06.6,ꢀ102.8,ꢀ83.6ꢀ(2ꢀC),ꢀ59.5,ꢀ55.9,ꢀ30.5,ꢀ30.0ꢀ29.5,ꢀ28.5,ꢀ28.3,ꢀ27.6,ꢀ23.7;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C20
H
27NO
3
ꢀ
+
ꢀNa] ꢀcalcdꢀ352.1883,ꢀfoundꢀ352.1902.ꢀ
ꢀ
Generalꢀ Procedureꢀ forꢀ theꢀ Synthesisꢀ ofꢀ α,β-Unsaturatedꢀ Aldehydes:ꢀ Toꢀ 4ꢀ mLꢀ borosilicateꢀ glassꢀ vialꢀ
containingꢀtheꢀalkylꢀenolꢀetherꢀ(1.00ꢀmmol),ꢀ1,4-benzoquinoneꢀ(130ꢀmg,ꢀ1.2ꢀmmol,ꢀ1.20ꢀequiv),ꢀwaterꢀ
(
20.0ꢀμL,ꢀ1.11ꢀmmol,ꢀ1.11ꢀequiv),ꢀAcOHꢀ(240ꢀμL,ꢀ4.19ꢀmmol,ꢀ4.19ꢀequiv)ꢀwasꢀaddedꢀPd(OAc)
CH Cl ꢀ(1.00ꢀmL).ꢀTheꢀreactionꢀwasꢀstirredꢀatꢀ23ꢀ°CꢀuntilꢀcompletionꢀasꢀindicatedꢀbyꢀGCꢀanalysis.ꢀTheꢀ
reactionꢀmixtureꢀwasꢀthenꢀdilutedꢀwithꢀCH Cl ꢀ(50ꢀmL)ꢀandꢀwashedꢀwithꢀwaterꢀ(50ꢀmL).ꢀTheꢀorganicꢀlayerꢀ
,ꢀreducedꢀunderꢀvacuumꢀandꢀtheꢀresultingꢀoilꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀ
2
ꢀfollowedꢀbyꢀ
2
2
2
2
wasꢀdriedꢀoverꢀNa
silicaꢀgel.ꢀ
2 4
SO
ꢀ
1
,2,3,6-tetrahydro-[1,1’-biphenyl]-4-carbaldehydeꢀ (1a):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ
usingꢀ(4-(methoxymethylene)cyclohexyl)benzeneꢀ(206ꢀmg,ꢀ1.02ꢀmmol)ꢀandꢀ2ꢀmolꢀ%ꢀPd(OAc) ꢀ(4.4ꢀmg,ꢀ
.02ꢀmmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(5ꢀ%ꢀEtOAc/hexanes)ꢀ
toꢀgiveꢀ1,2,3,6-tetrahydro-[1,1’-biphenyl]-4-carbaldehydeꢀ(160ꢀmg,ꢀ0.84ꢀmmol,ꢀ84%)ꢀasꢀaꢀclear,ꢀcolorlessꢀ
2
0
1
3
-1
oil.ꢀꢀSpectralꢀdataꢀofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀvalues. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3026,ꢀ2926,ꢀ
1
2
3
3
816,ꢀ1683,ꢀ1643,ꢀ1163,ꢀ700;ꢀ HꢀNMRꢀ(CDCl ,ꢀ400ꢀMHz):ꢀδꢀ9.49ꢀ(s,ꢀ1H),ꢀ7.34-7.30ꢀ(m,ꢀ2H),ꢀ7.25-7.21ꢀ(m,ꢀ
H),ꢀ6.89ꢀ(m,ꢀ1H),ꢀ2.90-2.82ꢀ(m,ꢀ1H),ꢀ2.71-2.62ꢀ(m,ꢀ1H),ꢀ2.55-2.41ꢀ(m,ꢀ2H),ꢀ2.29-2.18ꢀ(m,ꢀ1H),ꢀ2.09-2.03ꢀ
S7ꢀ
ꢀ

1
3
(
m,ꢀ1H),ꢀ1.78-1.68ꢀ(m,ꢀ1H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ194.0,ꢀ150.5,ꢀ145.7,ꢀ141.5,ꢀ128.7,ꢀ126.9,ꢀ126.6,ꢀ
+
ꢀ
3
9.9,ꢀ34.5,ꢀ28.8,ꢀ22.0;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C13
H
14Oꢀ+ꢀNa] ꢀcalcdꢀ209.0937,ꢀfoundꢀ209.0922.
ꢀ
(
E)-tridec-2-enalꢀ(2a):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ1-methoxytridec-1-eneꢀ(212ꢀmg,ꢀ
.00ꢀ mmol)ꢀ andꢀ 2ꢀ molꢀ %ꢀ Pd(OAc) ꢀ (4.6ꢀ mg,ꢀ 0.02ꢀ mmol).ꢀ ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ flashꢀ
chromatographyꢀonꢀsilicaꢀgelꢀ(2%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ(E)-tridec-1-enalꢀ(131ꢀmg,ꢀ0.67ꢀmmol,ꢀ67%)ꢀasꢀ
1
2
1
4
-1
aꢀclear,ꢀcolorlessꢀoil.ꢀSpectralꢀdataꢀofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀvalues. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ
1
2
925,ꢀ2854,ꢀ1695,ꢀ1466,ꢀ1138,ꢀ973;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.51ꢀ(d,ꢀJꢀ=ꢀ7.9ꢀHz,ꢀ1H),ꢀ6.85ꢀ(dt,ꢀJꢀ=ꢀ15.6ꢀ
Hz,ꢀ6.8ꢀHz,ꢀ1H),ꢀ6.12ꢀ(ddt,ꢀJꢀ=ꢀ15.6,ꢀ7.9,ꢀ1.4ꢀHz,ꢀ1H),ꢀ2.33ꢀ(m,ꢀ2H),ꢀ1.51ꢀ(m,ꢀ2H),ꢀ1.35-1.27ꢀ(m,ꢀ14H),ꢀ0.88ꢀ
1
3
(
t,ꢀJꢀ=ꢀ7.0ꢀHz,ꢀ3H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ194.1,ꢀ159.0,ꢀ133.1,ꢀ32.8,ꢀ32.0,ꢀ29.6ꢀ(2C),ꢀ29.4ꢀ(2C),ꢀ29.2,ꢀ
+
2
7.9,ꢀ22.7,ꢀ14.2;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C13H24Oꢀ+ꢀNa] ꢀcalcdꢀ219.1719,ꢀfoundꢀ219.1722.ꢀ
ꢀ
(
E)-4-phenylbut-2-enalꢀ (3a):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ (4-mehoxybut-3-en-1-
yl)benzeneꢀ(163ꢀmg,ꢀ1.00ꢀmmol)ꢀandꢀ1ꢀmolꢀ%ꢀPd(OAc) ꢀ(2.3ꢀmg,ꢀ0.02ꢀmmol).ꢀTheꢀcrudeꢀproductꢀwasꢀ
purifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(1:1ꢀCH Cl /hexanes)ꢀtoꢀgiveꢀ(E)-4-phenylbut-2-enalꢀ(95.4ꢀ
mg,ꢀ0.65ꢀmmol,ꢀ65%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀSpectralꢀdataꢀofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀ
2
2
2
1
5
-1
1
values. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3061,ꢀ3028,ꢀ2917,ꢀ2818,ꢀ1690,ꢀ1638,ꢀ1124,ꢀ700;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ
9
1
1
1
.52ꢀ(d,ꢀJꢀ=ꢀ7.9ꢀHz,ꢀ1H),ꢀ7.35-7.30ꢀ(m,ꢀ2H),ꢀ7.27-7.23ꢀ(m,ꢀ1H),ꢀ7.19-7.16ꢀ(m,ꢀ2H),ꢀ6.94ꢀ(dt,ꢀJꢀ=ꢀ15.7,ꢀ6.7ꢀHz,ꢀ
1
3
H),ꢀ6.10ꢀ(ddt,ꢀJꢀ=ꢀ15.7,ꢀ7.9,ꢀ1.6ꢀHz,ꢀ1H),ꢀ3.63ꢀ(dd,ꢀJꢀ=ꢀ4.3,ꢀ1.3ꢀHz,ꢀ2H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ193.8,ꢀ
+
56.4,ꢀ137.1,ꢀ133.6,ꢀ128.9ꢀ(2C),ꢀ127.0,ꢀ39.0;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C10
H10Oꢀ+ꢀNa] ꢀcalcdꢀ169.0629,ꢀfoundꢀ
ꢀ
69.0624.
ꢀ
ꢀ
(
E)-6-((tert-butyldimethylsilyl)oxy)hex-2-enalꢀ (4a):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ
tert-butyl((6-methoxyhex-5-en-1-yl)oxy)dimethylsilaneꢀ (244ꢀ mg,ꢀ 1.00ꢀ mmol)ꢀ andꢀ 2.5ꢀ molꢀ %ꢀ Pd(OAc)
5.6ꢀ mg,ꢀ 0.02ꢀ mmol).ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ flashꢀ chromatographyꢀ onꢀ silicaꢀ gelꢀ usingꢀ aꢀ
solventꢀ gradientꢀ (0-4%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ (E)-6-((tert-butyldimethylsilyl)oxy)hex-2-enalꢀ (130ꢀ mg,ꢀ
.70ꢀ mmol,ꢀ 57%)ꢀ asꢀ aꢀ clear,ꢀ colorlessꢀ oil.ꢀ Spectralꢀ dataꢀ ofꢀ theꢀ productꢀ matchedꢀ reportedꢀ literatureꢀ
2
ꢀ
(
0
1
6
-1
1
values. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2930,ꢀ2857,ꢀ1694,ꢀ1462,ꢀ1256,ꢀ1105,ꢀ838;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.46ꢀ(d,ꢀ
Jꢀ=ꢀ7.9,ꢀ1H),ꢀ6.85ꢀ(dt,ꢀJꢀ=ꢀ15.6,ꢀ6.8,ꢀ1H),ꢀ6.09ꢀ(ddt,ꢀJꢀ=ꢀ15.6,ꢀ7.9,ꢀ1.5,ꢀ1H),ꢀ3.62ꢀ(t,ꢀJꢀ=ꢀ6.1,ꢀ2H),ꢀ2.42-2.36ꢀ(m,ꢀ
1
3
2
3
H),ꢀ1.72-1.65ꢀ(m,ꢀ2H),ꢀ0.86ꢀ(s,ꢀ9H),ꢀ0.01ꢀ(s,ꢀ6H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδ193.9,ꢀ158.5,ꢀ133.0,ꢀ62.0,ꢀ
ꢀ
0.9,ꢀ29.3,ꢀ25.9,ꢀ18.2,ꢀ-5.4.
S8ꢀ
ꢀ

ꢀ
ꢀ
(
E)-6-oxohex-4-en-1-ylꢀacetateꢀ(5a):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ6-methoxyhex-5-
en-1-ylꢀacetateꢀ(172ꢀmg,ꢀ1.00ꢀmmol)ꢀandꢀ1ꢀmolꢀ%ꢀPd(OAc)
2
ꢀ(2.4ꢀmg,ꢀ0.02ꢀmmol).ꢀTheꢀcrudeꢀproductꢀwasꢀ
purifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀusingꢀaꢀsolventꢀgradientꢀ(10%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ(E)-
-
1
6
1
-oxohex-4-en-1-ylꢀacetateꢀ(125ꢀmg,ꢀ0.80ꢀmmol,ꢀ80%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2955,ꢀ
1
3
734,ꢀ1686,ꢀ1367,ꢀ1242,ꢀ1045;ꢀ HꢀNMRꢀ(CDCl ,ꢀ400ꢀMHz):ꢀδꢀ9.52ꢀ(d,ꢀJꢀ=ꢀ8.0ꢀHz,ꢀ1H),ꢀ6.87ꢀ(dt,ꢀJꢀ=ꢀ15.6,ꢀ6.8ꢀ
Hz,ꢀ1H),ꢀ(qt,ꢀJꢀ=ꢀ7.6,ꢀ1.6ꢀHz,ꢀ1H),ꢀ4.12ꢀ(t,ꢀJꢀ=ꢀ6.4ꢀHz,ꢀ2H),ꢀ2.47-2.41ꢀ(m,ꢀ2H),ꢀ2.06ꢀ(s,ꢀ1H),ꢀ1.87ꢀ(quin,ꢀJꢀ=ꢀ6.4ꢀ
1
3
Hz,ꢀ2H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ193.7,ꢀ170.9,ꢀ156.9,ꢀ133.3,ꢀ63.2,ꢀ29.1,ꢀ26.8,ꢀ20.8;ꢀHRMSꢀ(ES)ꢀcalcdꢀ
+
forꢀ[C H O ꢀ+ꢀNa] ꢀcalcdꢀ179.0679,ꢀfoundꢀ179.0671.ꢀ
8 12 3
ꢀ
(
2E,ꢀ 6Z)-7-(triethylsilyl)hepta-2,6-dienalꢀ (6a):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ
triethyl((1Z)-7-methoxyhepta-1,6-dienalꢀ (246ꢀ mg,ꢀ 1.03ꢀ mmol)ꢀ andꢀ 4ꢀ molꢀ %ꢀ Pd(OAc) ꢀ (8.9ꢀ mg,ꢀ 0.04ꢀ
2
mmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(2ꢀ%ꢀEtOAc/hexanes)ꢀtoꢀ
giveꢀ (2E,ꢀ 6Z)-7-(triethylsilyl)hepta-2,6-dienalꢀ (159ꢀ mg,ꢀ 0.69ꢀ mmol,ꢀ 69%)ꢀ asꢀ aꢀ clear,ꢀ colorlessꢀ oil.ꢀ ꢀ FTIRꢀ
-
1
1
(
film,ꢀcm ):ꢀ2954,ꢀ2909,ꢀ2874,ꢀ2819,ꢀ1686,ꢀ1605,ꢀ1458,ꢀ1123,ꢀ1015;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.51ꢀ(d,ꢀ
Jꢀ=ꢀ7.6ꢀHz,ꢀ1H),ꢀ6.85ꢀ(dt,ꢀJꢀ=ꢀ15.6,ꢀ6.8ꢀHz,ꢀ1H),ꢀ6.38-6.31ꢀ(m,ꢀ1H),ꢀ6.17-6.11ꢀ(m,ꢀ1H),ꢀ5.52ꢀ(d,ꢀJꢀ=ꢀ14.4ꢀHz,ꢀ
1
3
1
H),ꢀ2.43ꢀ(q,ꢀJꢀ=ꢀ6.8ꢀHz,ꢀ2H),ꢀ2.33ꢀ(q,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ2H),ꢀ0.95ꢀ(t,ꢀJꢀ=ꢀ7.6ꢀHz,ꢀ9H),ꢀ0.62ꢀ(q,ꢀJꢀ=ꢀ8.0ꢀHz,ꢀ6H);ꢀ Cꢀ
NMRꢀ(CDCl ,ꢀ100ꢀMHz):ꢀδꢀ193.7,ꢀ157.3,ꢀ147.2,ꢀ133.2,ꢀ127.4,ꢀ32.6,ꢀ32.0,ꢀ7.4,ꢀ4.6;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ
24NOSiꢀ+ꢀNa] ꢀcalcdꢀ247.1489,ꢀfoundꢀ247.1499.ꢀ
3
+
13
[C H
ꢀ
1
,4-dioxaspiro[4.5]dec-7-ene-8-carbaldehydeꢀ(7a):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ8-
methoxymethylene)-1,4-dioxaspiro[4.5]decaneꢀ(183ꢀmg,ꢀ1.00ꢀmmol)ꢀandꢀ2.5ꢀmolꢀ%ꢀPd(OAc) ꢀ(5.6ꢀmg,ꢀ
.02ꢀmmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(10%ꢀEtOAc/hexanes)ꢀ
(
2
0
toꢀgiveꢀ1,4-dioxaspiro[4.5]dec-7-ene-8-carbaldehydeꢀ(129ꢀmg,ꢀ0.77ꢀmmol,ꢀ77%)ꢀasꢀaꢀclear,ꢀcolorlessꢀoil.ꢀꢀ
-
1
1
FTIRꢀ(film,ꢀcm ):ꢀ2958,ꢀ2887,ꢀ2821,ꢀ1683,ꢀ1117,ꢀ1061;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.39ꢀ(s,ꢀ1H),ꢀ6.63ꢀ(t,ꢀJꢀ
1
3
=
ꢀ2.0ꢀHz),ꢀ3.94ꢀ(s,ꢀ4H),ꢀ2.52ꢀ(t,ꢀJꢀ=ꢀ0.8ꢀHz,ꢀ2H),ꢀ2.38ꢀ(td,ꢀJꢀ=ꢀ5.2,ꢀ2.8ꢀHz,ꢀ2H),ꢀ1.73ꢀ(t,ꢀJꢀ=ꢀ6.4ꢀHz,ꢀ2H);ꢀ Cꢀ
NMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ193.2,ꢀ147.4,ꢀ140.8,ꢀ107.6,ꢀ64.7,ꢀ37.0,ꢀ30.2,ꢀ20.5;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C
9
H
12
O
3
ꢀ
+
+
ꢀNa] ꢀcalcdꢀ191.0679,ꢀfoundꢀ191.0675.ꢀ
S9ꢀ
ꢀ

ꢀ
4
-(tert-butyl)cyclohex-1-enecarbaldehydeꢀ (8a):ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ 1-
(
tert-butyl)-4-(methoxymethylene)cyclohexaneꢀ(182ꢀmg,ꢀ1.00ꢀmmol)ꢀandꢀ2ꢀmolꢀ%ꢀPd(OAc)
mmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀusingꢀaꢀsolventꢀgradientꢀ
5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ4-(tert-butyl)cyclohex-1-enecarbaldehydeꢀ(153ꢀmg,ꢀ0.92ꢀmmol,ꢀ92%)ꢀasꢀaꢀ
2
ꢀ(4.5ꢀmg,ꢀ0.02ꢀ
(
1
7ꢀ
-1
clear,ꢀcolorlessꢀoil.ꢀꢀSpectralꢀdataꢀofꢀtheꢀproductꢀmatchedꢀreportedꢀliteratureꢀvalues. ꢀFTIRꢀ(film,ꢀcm ):ꢀ
1
2
2
1
961,ꢀ2869,ꢀ2819,ꢀ1678,ꢀ1645,ꢀ1396,ꢀ1365,ꢀ1159;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.43ꢀ(s,ꢀ1H),ꢀ6.82ꢀ(m,ꢀ1H),ꢀ
1
3
.52-2.39ꢀ(m,ꢀ2H),ꢀ2.11-1.94ꢀ(m,ꢀ2H),ꢀ1.37-1.31ꢀ(m,ꢀ1H),ꢀ1.17-1.09ꢀ(m,ꢀ1H),ꢀ0.91ꢀ(s,ꢀ9H);ꢀ CꢀNMRꢀ(CDCl
00ꢀMHz):ꢀδꢀ193.7,ꢀ151.6,ꢀ141.4,ꢀ43.9,ꢀ32.1,ꢀ28.2,ꢀ26.9,ꢀ22.7,ꢀ22.4.ꢀ
3
,ꢀ
ꢀ
(
E)-6-(1,3-dioxoisoindolin-2-yl)hex-2-enalꢀ(9a):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀ2-(6-
methoxyhex-5-en-1-yl)isoindoline-1,3-dioneꢀ(262ꢀmg,ꢀ1.01ꢀmmol)ꢀandꢀ2.5ꢀmolꢀ%ꢀPd(OAc) ꢀ(5.6ꢀmg,ꢀ0.025ꢀ
2
mmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(25ꢀ%ꢀEtOAc/hexanes)ꢀtoꢀ
-
giveꢀ(E)-6-(1,3-dioxoisoindolin-2-yl)hex-2-enalꢀ(180ꢀmg,ꢀ0.73ꢀmmol,ꢀ73%)ꢀasꢀaꢀwhiteꢀsolid.ꢀꢀFTIRꢀ(film,ꢀcm
1
1
)
:ꢀ3032,ꢀ2936,ꢀ2856,ꢀ1770,ꢀ1713,ꢀ1395,ꢀ1208,ꢀ1106;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.48ꢀ(d,ꢀJꢀ=ꢀ7.6ꢀHz,ꢀ1H),ꢀ
7
2
1
.88-7.83ꢀ(m,ꢀ2H),ꢀ7.76-7.71ꢀ(m,ꢀ2H),ꢀ6.85ꢀ(dt,ꢀJꢀ=ꢀ16.0,ꢀ6.4ꢀHz,ꢀ1H),ꢀ6.18-6.12ꢀ(m,ꢀ1H),ꢀ3.76ꢀ(t,ꢀJꢀ=ꢀ7.2ꢀHz,ꢀ
1
3
H),ꢀ2.45-2.39ꢀ(m,ꢀ2H),ꢀ1.97-1.89ꢀ(m,ꢀ2H);ꢀ CꢀNMRꢀ(CDCl
31.9,ꢀ123.2,ꢀ37.1,ꢀ29.9,ꢀ26.7;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C14
3
,ꢀ100ꢀMHz):ꢀδꢀ193.6,ꢀ168.2,ꢀ156.5,ꢀ134.0,ꢀ133.4,ꢀ
+
H
3
13NO ꢀ+ꢀNa] ꢀcalcdꢀ266.0788,ꢀfoundꢀ266.0790.ꢀ
ꢀ
6
-(2,5-dioxopyrrolidin-1-yl)hexanalꢀ(10a):ꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀfollowedꢀusingꢀusingꢀ1-(6-
ꢀ(5.6ꢀmg,ꢀ0.025ꢀ
methoxyhex-5-en-1-yl)pyrrolidine-2,5-dioneꢀ(210ꢀmg,ꢀ1.00ꢀmmol)ꢀandꢀ2.5ꢀmolꢀ%ꢀPd(OAc)
2
mmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(30-40%ꢀEtOAc/hexanes)ꢀtoꢀ
giveꢀ(E)-6-(2,5-dioxopyrrolidin-1-yl)hex-2-enalꢀ(145ꢀmg,ꢀ0.74ꢀmmol,ꢀ74%)ꢀasꢀaꢀpaleꢀyellowꢀoil.ꢀꢀFTIRꢀ(film,ꢀ
-
1
1
cm ):ꢀ2944,ꢀ2829,ꢀ1693,ꢀ1440,ꢀ1402,ꢀ1163,ꢀ1137;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.51-9.48ꢀ(m,ꢀ1H),ꢀ6.88-
6
2
.79ꢀ(m,ꢀ1H),ꢀ6.17-6.09ꢀ(m,ꢀ1H),ꢀ3.58-3.53ꢀ(m,ꢀ2H),ꢀ2.73-2.71ꢀ(m,ꢀ4H),ꢀ2.39-2.34ꢀ(m,ꢀ2H),ꢀ1.85-1.77ꢀ(m,ꢀ
1
3
H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ193.8,ꢀ177.3,ꢀ156.6,ꢀ133.4,ꢀ38.0,ꢀ29.9,ꢀ28.2,ꢀ25.9;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ
+
[
C
10
H
13NO
3
ꢀ+ꢀNa] ꢀcalcdꢀ218.0788,ꢀfoundꢀ218.0781.ꢀ
S10ꢀ
ꢀ

ꢀ
6
,7-dihydro-5H-benzo[7]annulene-9-carbaldehydeꢀ (11a):ꢀ Aꢀ slightꢀ modificationꢀ toꢀ theꢀ aboveꢀ generalꢀ
procedureꢀwasꢀfollowed.ꢀToꢀ4ꢀmLꢀborosilicateꢀglassꢀvialꢀcontainingꢀtheꢀ5-(methoxymethylene)-6,7,8,9-
tetrahydro-5H-benzo[7]annuleneꢀ (189ꢀ mg,ꢀ 1.00ꢀ mmol),ꢀ 1,4-benzoquinoneꢀ (132ꢀ mg,ꢀ 1.2ꢀ mmol,ꢀ 1.2ꢀ
equiv),ꢀandꢀwaterꢀ(20.0ꢀμL,ꢀ1.11ꢀmmol,ꢀ1.11ꢀequiv)ꢀwasꢀaddedꢀ5ꢀmolꢀ%ꢀPd(OAc)
followedꢀ byꢀ AcOHꢀ (1.00ꢀ mL).ꢀ Theꢀ reactionꢀ wasꢀ stirredꢀ atꢀ 40ꢀ °Cꢀ untilꢀ completionꢀ asꢀ indicatedꢀ byꢀ GCꢀ
analysis.ꢀTheꢀreactionꢀmixtureꢀwasꢀthenꢀdilutedꢀwithꢀCH Cl ꢀ(50ꢀmL)ꢀandꢀwashedꢀwithꢀwaterꢀ(50ꢀmL).ꢀTheꢀ
organicꢀlayerꢀwasꢀdriedꢀoverꢀNa SO ,ꢀreducedꢀunderꢀvacuumꢀandꢀtheꢀcrudeꢀproductꢀpurifiedꢀbyꢀflashꢀ
chromatographyꢀ onꢀ silicaꢀ gelꢀ (5%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ (E)-6-(benzyloxy)hex-2-enalꢀ (123ꢀ mg,ꢀ 0.71ꢀ
2
ꢀ(11.5ꢀmg,ꢀ0.05ꢀmmol)ꢀ
2
2
2
4
-
1
mmol,ꢀ71%)ꢀasꢀaꢀclear,ꢀpaleꢀorangeꢀoil.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3055,ꢀ2932,ꢀ2857,ꢀ1690,ꢀ1448,ꢀ1226,ꢀ1120,ꢀ
1
1
075;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.66ꢀ(s,ꢀ1H),ꢀ7.44-7.14ꢀ(m,ꢀ5H),ꢀ2.55-2.52ꢀ(m,ꢀ2H),ꢀ2.23-2.22ꢀ(m,ꢀ4H);ꢀ
1
3
CꢀNMRꢀ(CDCl
6.3;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C12H12Oꢀ+ꢀNa] ꢀcalcdꢀ195.0780,ꢀfoundꢀ195.0779.ꢀ
3
,ꢀ100ꢀMHz):ꢀδꢀ192.6,ꢀ154.9,ꢀ143.6,ꢀ141.2,ꢀ132.7,ꢀ129.2,ꢀ129.1,ꢀ128.3,ꢀ126.1,ꢀ33.9,ꢀ32.1,ꢀ
+
2
ꢀ
-cyclohexylidene-2-phenylacetaldehydeꢀ(12a):ꢀAꢀslightꢀmodificationꢀtoꢀtheꢀaboveꢀgeneralꢀprocedureꢀ
2
wasꢀfollowed.ꢀToꢀ4ꢀmLꢀborosilicateꢀglassꢀvialꢀcontainingꢀ(1-cyclohexyl-2-methoxyvinyl)benzeneꢀ(216ꢀmg,ꢀ
.00ꢀmmol),ꢀ1,4-benzoquinoneꢀ(130ꢀmg,ꢀ1.20ꢀmmol,ꢀ1.2ꢀequiv),ꢀandꢀwaterꢀ(20.0ꢀμL,ꢀ1.11ꢀmmol,ꢀ1.11ꢀ
equiv)ꢀwasꢀaddedꢀ10ꢀmolꢀ%ꢀPd(OAc) ꢀ(22.4ꢀmg,ꢀ0.10ꢀmmol,ꢀ0.10ꢀequiv)ꢀfollowedꢀbyꢀAcOHꢀ(1.00ꢀmL).ꢀTheꢀ
reactionꢀwasꢀstirredꢀatꢀ23ꢀ°Cꢀforꢀ4ꢀd.ꢀTheꢀreactionꢀmixtureꢀwasꢀthenꢀdilutedꢀwithꢀCH Cl ꢀ(50ꢀmL)ꢀandꢀ
washedꢀwithꢀwaterꢀ(50ꢀmL).ꢀTheꢀorganicꢀlayerꢀwasꢀdriedꢀoverꢀNa SO ,ꢀreducedꢀunderꢀvacuumꢀandꢀtheꢀ
crudeꢀ productꢀ purifiedꢀ byꢀ flashꢀ chromatographyꢀ onꢀ silicaꢀ gelꢀ (1%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ 2-
1
2
2
2
2
4
-
1
cyclohexylidene-2-phenylacetaldehydeꢀ(115ꢀmg,ꢀ0.58ꢀmmol,ꢀ58%)ꢀasꢀaꢀlightꢀbrownꢀoil.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ
1
2
7
1
935,ꢀ2857,ꢀ1683,ꢀ1448,ꢀ1274,ꢀ1149;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ10.3ꢀ(s,ꢀ1H),ꢀ7.38-7.26ꢀ(m,ꢀ3H),ꢀ7.05-
1
3
3
.03ꢀ(m,ꢀ2H),ꢀ2.90-2.87ꢀ(m,ꢀ2H),ꢀ2.21-2.18ꢀ(m,ꢀ2H),ꢀ1.84-1.81ꢀ(m,ꢀ2H),ꢀ1.84-1.62ꢀ(m,ꢀ4H);ꢀ CꢀNMRꢀ(CDCl ,ꢀ
00ꢀMHz):ꢀδꢀ189.7,ꢀ164.1,ꢀ136.6,ꢀ135.9,ꢀ129.9,ꢀ128.2,ꢀ127.2ꢀ34.6,ꢀ29.6,ꢀ28.9,ꢀ28.6,ꢀ26.4;ꢀHRMSꢀ(ES)ꢀcalcdꢀ
+
forꢀ[C14
H
16Oꢀ+ꢀNa] ꢀcalcdꢀ223.1093,ꢀfoundꢀ223.1092.ꢀ
ꢀ
(
E)-4,8-dimethylnona-2,7-dienalꢀ (13a):ꢀ ꢀ Theꢀ aboveꢀ generalꢀ procedureꢀ wasꢀ followedꢀ usingꢀ usingꢀ 1-
methoxy-4,8-dimethylnona-1,7-dieneꢀ (183ꢀ mg,ꢀ 1.00ꢀ mmol)ꢀ andꢀ 5ꢀ molꢀ %ꢀ Pd(OAc) ꢀ (11.2ꢀ mg,ꢀ 0.050ꢀ
2
mmol).ꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀflashꢀchromatographyꢀonꢀsilicaꢀgelꢀ(3-5ꢀ%ꢀEtOAc/hexanes)ꢀtoꢀ
S11ꢀ
ꢀ

giveꢀ(E)-4,8-dimethylnona-2,7-dienalꢀ(123ꢀmg,ꢀ0.74ꢀmmol,ꢀ74%)ꢀasꢀaꢀcolorlessꢀoil.ꢀꢀSpectralꢀdataꢀofꢀtheꢀ
1
2
-1
productꢀmatchedꢀreportedꢀliteratureꢀvalues. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2964,ꢀ2926,ꢀ2728,ꢀ1693,ꢀ1634,ꢀ1454,ꢀ
1
1
1
3
1
1
377,ꢀ1144,ꢀ1124,ꢀ978;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.51ꢀ(d,ꢀJꢀ=ꢀ7.8ꢀHz,ꢀ1H),ꢀ6.74ꢀ(dd,ꢀJꢀ=ꢀ15.7,ꢀ7.6ꢀHz,ꢀ
H),ꢀ(ddd,ꢀJꢀ=ꢀ15.6,ꢀ7.8,ꢀ1.2ꢀHz,ꢀ1H),ꢀ5.10-5.05ꢀ(m,ꢀ1H),ꢀ2.52-2.41ꢀ(m,ꢀ1H),ꢀ1.99ꢀ(q,ꢀJꢀ=ꢀ7.5ꢀHz,ꢀ2H),ꢀ1.68ꢀ(m,ꢀ
1
3
H),ꢀ1.59ꢀ(m,ꢀ3H),ꢀ1.50-1.43ꢀ(m,ꢀ2H),ꢀ1.10ꢀ(d,ꢀJꢀ=ꢀ6.8ꢀHz,ꢀ3H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ194.2,ꢀ164.1,ꢀ
+
32.1,ꢀ 131.3,ꢀ 123.6,ꢀ 36.5,ꢀ 35.9,ꢀ 25.6,ꢀ 25.5,ꢀ 19.1,ꢀ 17.7;ꢀ HRMSꢀ (ES)ꢀ calcdꢀ forꢀ [C11
89.1250,ꢀfoundꢀ189.1257.ꢀ
H
18Oꢀ +ꢀ Na] ꢀ calcdꢀ
ꢀ
(
E)-tert-butylꢀ2-(6-oxohex-4-en-1-yl)-1H-indole-1-carboxylateꢀ(14a):ꢀꢀTheꢀaboveꢀgeneralꢀprocedureꢀwasꢀ
followedꢀ usingꢀ usingꢀ tert-butylꢀ 2-(6-methoxyhex-5-en-1-yl)-1H-indole-1-carboxylateꢀ (330ꢀ mg,ꢀ 1.00ꢀ
mmol)ꢀ andꢀ 5ꢀ molꢀ %ꢀ Pd(OAc) ꢀ (11.2ꢀ mg,ꢀ 0.050ꢀ mmol).ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ flashꢀ
2
chromatographyꢀ onꢀ silicaꢀ gelꢀ (3%ꢀ EtOAc/hexanes)ꢀ toꢀ giveꢀ (E)-tert-butylꢀ 2-(6-oxohex-4-en-1-yl)-1H-
indole-1-carboxylateꢀ (143ꢀ mg,ꢀ 0.45ꢀ mmol,ꢀ 45%)ꢀ asꢀ aꢀ paleꢀ yellowꢀ oil.ꢀ ꢀ Spectralꢀ dataꢀ ofꢀ theꢀ productꢀ
1
8
-1
matchedꢀreportedꢀliteratureꢀvalues. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ2977,ꢀ1731,ꢀ1690,ꢀ1454,ꢀ1370,ꢀ1329,ꢀ1158,ꢀ1116,ꢀ
1
1
7
1
087,ꢀ747;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ9.52ꢀ(d,ꢀJꢀ=ꢀ7.9ꢀHz,ꢀ1H),ꢀ8.06ꢀ(d,ꢀJꢀ=ꢀ8.5ꢀHz,ꢀ1H),ꢀ7.49-7.45ꢀ(m,ꢀ1H),ꢀ
.24-7.17ꢀ(m,ꢀ2H),ꢀ6.89ꢀ(dt,ꢀJꢀ=ꢀ15.6,ꢀ6.7ꢀHz,ꢀ1H),ꢀ6.36ꢀ(d,ꢀJꢀ=ꢀ0.7ꢀHz,ꢀ1H),ꢀ6.17ꢀ(dtt,ꢀJꢀ=ꢀ16.4,ꢀ7.9,ꢀ1.5ꢀHz,ꢀ
1
3
3
H),ꢀ3.08ꢀ(t,ꢀJꢀ=ꢀ7.4ꢀHz,ꢀ2H),ꢀ2.46ꢀ(m,ꢀ2H),ꢀ1.94ꢀ(p,ꢀJꢀ=ꢀ7.4ꢀHz,ꢀ2H),ꢀ1.69ꢀ(s,ꢀ9H);ꢀ CꢀNMRꢀ(CDCl ,ꢀ100ꢀMHz):ꢀ
δꢀ 193.9,ꢀ 158.1,ꢀ 150.5,ꢀ 141.1,ꢀ 136.6,ꢀ 133.3,ꢀ 129.2,ꢀ 123.5,ꢀ 122.7,ꢀ 119.8,ꢀ 115.6,ꢀ 107.6,ꢀ 83.9,ꢀ 32.2,ꢀ 29.5,ꢀ
+
2
8.3,ꢀ27.1;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C19
H
23NO
3
ꢀ+ꢀNa] ꢀcalcdꢀ336.1570,ꢀfoundꢀ336.1587.ꢀ
ꢀ
Generalꢀ procedureꢀ forꢀ theꢀ preparationꢀ ofꢀ 4-hydroxyꢀ enolꢀ ethers:ꢀ ꢀ Toꢀ aꢀ solutionꢀ ofꢀ sBuLiꢀ (1.4ꢀ Mꢀ inꢀ
cyclohexane,ꢀ 1.3ꢀ equiv)ꢀ inꢀ THFꢀ cooledꢀ toꢀ -78ꢀ ⁰Cꢀ wasꢀ addedꢀ allylꢀ alkylꢀ etherꢀ (1.3ꢀ equiv).ꢀ ꢀ Theꢀ yellowꢀ
solutionꢀwasꢀallowedꢀtoꢀstirꢀforꢀ15ꢀminꢀthenꢀaldehydeꢀorꢀketoneꢀ(1ꢀequiv)ꢀwasꢀaddedꢀandꢀallowedꢀtoꢀstirꢀ
atꢀ-78ꢀ⁰Cꢀforꢀ0.5ꢀhꢀandꢀ2ꢀhꢀatꢀ24ꢀ⁰C.ꢀꢀTheꢀreactionꢀwasꢀquenchedꢀwithꢀsat.ꢀNH
separatedꢀandꢀtheꢀaqueousꢀlayerꢀwasꢀextractedꢀwithꢀCH Cl ꢀ(3x),ꢀtheꢀcombinedꢀorganicꢀlayersꢀwereꢀdriedꢀ
overꢀNa SO ,ꢀdecanted,ꢀconcentratedꢀunderꢀreducedꢀpressure,ꢀandꢀꢀpurifiedꢀꢀbyꢀcolumnꢀchromatographyꢀ
onꢀsilicaꢀgelꢀ(EtOAc/hexane)ꢀtoꢀaffordꢀpureꢀ4-hydroxyꢀenolꢀether.ꢀ
4
Cl(aq),ꢀtheꢀorganicꢀlayerꢀwasꢀ
2
2
2
4
ꢀ
(
Z)-6-methoxy-1-phenylhex-5-en-3-olꢀ(15):ꢀꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀgeneralꢀ
procedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀ3-phenylpropionaldehydeꢀ(2.64ꢀmL,ꢀ2.69ꢀg,ꢀ20.0ꢀmmol,ꢀ1ꢀ
S12ꢀ
ꢀ

2
equiv),ꢀallylꢀmethylꢀether ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(20ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ37%ꢀofꢀtheꢀproductꢀ(1.5423ꢀg,ꢀ7.48ꢀmmol)ꢀasꢀaꢀ
-
1
1
colorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3386,ꢀ3025,ꢀ2932,ꢀ1664,ꢀ1453,ꢀ1258,ꢀ1108,ꢀ699;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀ
MHz):ꢀδꢀ7.29-7.15ꢀ(m,ꢀ5H),ꢀ6.02ꢀ(dt,ꢀJꢀ=ꢀ6.3,ꢀ1.2ꢀHz,ꢀ1H),ꢀ4.40ꢀ(dt,ꢀJꢀ=ꢀ7.6,ꢀ6.3ꢀHz,ꢀ1H),ꢀ3.68-3.62ꢀ(m,ꢀ1H),ꢀ
1
3
3
.58ꢀ(s,ꢀ3H),ꢀ2.83-2.63ꢀ(m,ꢀ2H),ꢀ2.28-2.24ꢀ(m,ꢀ2H),ꢀ2.03ꢀ(brꢀs,ꢀ1H),ꢀ1.80-1.74ꢀ(m,ꢀ2H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀ
MHz):ꢀδꢀ148.4,ꢀ142.4,ꢀ128.5,ꢀ128.4,ꢀ125.7,ꢀ101.8,ꢀ71.0,ꢀ59.6,ꢀ38.6,ꢀ32.1ꢀ(2ꢀC);ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ
+
[
13 18 2
C H O ꢀ+ꢀNa] ꢀcalcdꢀ229.1199,ꢀfoundꢀ257.1198.ꢀ
ꢀ
(
Z)-6-ethoxy-1-phenylhex-5-en-3-olꢀ(16):ꢀꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀgeneralꢀ
procedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀ3-phenylpropionaldehydeꢀ(0.66ꢀmL,ꢀ0.53ꢀg,ꢀ5.0ꢀmmol,ꢀ1ꢀ
equiv),ꢀallylꢀethylꢀetherꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(5ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ36%ꢀofꢀtheꢀproductꢀ(0.393ꢀg,ꢀ1.78ꢀmmol)ꢀasꢀaꢀ
-
1
1
colorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3386,ꢀ3026,ꢀ2977,ꢀ2930,ꢀ1664,ꢀ1381,ꢀ1110,ꢀ746ꢀ699;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀ
MHz):ꢀδꢀ7.30-7.16ꢀ(m,ꢀ5H),ꢀ6.11ꢀ(dt,ꢀJꢀ=ꢀ6.3,ꢀ1.2ꢀHz,ꢀ1H),ꢀ4.41ꢀ(dt,ꢀJꢀ=ꢀ7.5,ꢀ6.3ꢀHz,ꢀ1H),ꢀ3.81ꢀ(q,ꢀJꢀ=ꢀ7.0ꢀHz,ꢀ
2
1
3
H),ꢀ3.70-3.63ꢀ(m,ꢀ1H),ꢀ2.85-2.64ꢀ(m,ꢀ2H),ꢀ2.30-2.26ꢀ(m,ꢀ2H),ꢀ1.98ꢀ(d,ꢀJꢀ=ꢀ4.4ꢀHz,ꢀ1H),ꢀ1.82-1.76ꢀ(m,ꢀ2H),ꢀ
1
3
.25ꢀ(t,ꢀJꢀ=ꢀ7.0ꢀHz,ꢀ3H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ147.0,ꢀ142.4,ꢀ128.5,ꢀ128.3,ꢀ125.7,ꢀ101.7,ꢀ71.1,ꢀ67.8,ꢀ
+
8.5,ꢀ32.2,ꢀ32.1,ꢀ15.3;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C14
20 2
H O ꢀ+ꢀNa] ꢀcalcdꢀ243.1356,ꢀfoundꢀ243.1353.ꢀ
ꢀ
Z)-6-isopropoxy-1-phenylhex-5-en-3-olꢀ (17):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ toꢀ theꢀ generalꢀ
(
procedureꢀ forꢀ 4-hydroxyꢀ enolꢀ ethersꢀ usingꢀ 3-phenylpropionaldehydeꢀ (2.10ꢀ mL,ꢀ 2.14ꢀ g,ꢀ 15.9ꢀ mmol,ꢀ 1ꢀ
1
equiv),ꢀallylꢀisopropylꢀether ꢀ(2.10ꢀmL,ꢀ2.14ꢀg,ꢀ15.9ꢀmmol,ꢀ1ꢀequiv),ꢀꢀandꢀTHFꢀ(50ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀ
wasꢀpurifiedꢀbyꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ28%ꢀofꢀtheꢀproductꢀ
-
1
(
1.0461ꢀg,ꢀ4.46ꢀmmol)ꢀasꢀaꢀcolorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3381,ꢀ3027,ꢀ2974,ꢀ2931,ꢀ1662,ꢀ1602,ꢀ1453,ꢀ
1
1
337,ꢀ1109,ꢀ1054,ꢀ699;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.92-7.15ꢀ(m,ꢀ5H),ꢀ6.13ꢀ(dt,ꢀJꢀ=ꢀ6.4,ꢀ1.2ꢀHz,ꢀ1H),ꢀ4.41ꢀ
(
dt,ꢀJꢀ=ꢀ7.5,ꢀ6.4ꢀHz,ꢀ1H),ꢀ3.92ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1H),ꢀ3.70-3.63ꢀ(m,ꢀ1H),ꢀ2.84-2.64ꢀ(m,ꢀ2H),ꢀ2.29-2.25ꢀ(m,ꢀ2H),ꢀ
1
3
2
1
.05ꢀ(d,ꢀJꢀ=ꢀ4.2ꢀHz,ꢀ1H),ꢀ1.81-1.75ꢀ(m,ꢀ2H),ꢀ1.22ꢀ(d,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ6H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ145.9,ꢀ
+
42.4,ꢀ128.5,ꢀ128.3,ꢀ125.7,ꢀ101.8,ꢀ74.3,ꢀ71.2,ꢀ38.5,ꢀ32.3,ꢀ32.1,ꢀ22.4;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C15
22 2
H O ꢀ+ꢀNa] ꢀ
calcdꢀ257.1512,ꢀfoundꢀ257.1508.ꢀ
ꢀ
S13ꢀ
ꢀ

(
Z)-6-(tert-pentyloxy)-1-phenylhex-5-en-3-olꢀ(18):ꢀꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀ
generalꢀprocedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀ3-phenylpropionaldehydeꢀ(0.80ꢀmL,ꢀ0.82ꢀg,ꢀ6.0ꢀmmol,ꢀ
3
1
ꢀequiv),ꢀ2-(allyloxy)-2-methylbutane ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(15ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀ
columnꢀchromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ15%ꢀofꢀtheꢀproductꢀ(0.242ꢀg,ꢀ0.923ꢀ
-
1
mmol)ꢀasꢀaꢀcolorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3395,ꢀ3026,ꢀ2973,ꢀ2932,ꢀ1658,ꢀ1454,ꢀ1368,ꢀ1246,ꢀ1172,ꢀ1059,ꢀ
1
6
1
=
1
99;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.28-7.14ꢀ(m,ꢀ5H),ꢀ6.30ꢀ(dt,ꢀJꢀ=ꢀ6.4,ꢀ1.1ꢀHz,ꢀ1H),ꢀ4.45ꢀ(dt,ꢀJꢀ=ꢀ7.5,ꢀ6.4ꢀHz,ꢀ
H),ꢀ3.69-3.63ꢀ(m,ꢀ1H),ꢀ2.84-2.63ꢀ(m,ꢀ2H),ꢀ2.38ꢀ(brꢀs,ꢀ1H),ꢀ2.29-2.26ꢀ(m,ꢀ2H),ꢀ1.81-1.74ꢀ(m,ꢀ2H),ꢀ1.55ꢀ(q,ꢀJꢀ
1
3
ꢀ7.5ꢀHz,ꢀ2H),ꢀ1.21ꢀ(s,ꢀ6H),ꢀ0.88ꢀ(t,ꢀJꢀ=ꢀ7.5ꢀHz,ꢀ3H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ142.5,ꢀ141.0,ꢀ128.5,ꢀ
28.4,ꢀ128.3,ꢀ125.7,ꢀ102.6,ꢀ78.4,ꢀ71.3,ꢀ38.6,ꢀ33.5,ꢀ32.3,ꢀ32.2,ꢀ25.5,ꢀ8.2;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C17
26 2
H O ꢀ+ꢀ
+
Na] ꢀcalcdꢀ285.1825,ꢀfoundꢀ285.1828.ꢀ
ꢀ
(
Z)-6-phenoxy-1-phenylhex-5-en-3-olꢀ(19):ꢀꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀgeneralꢀ
procedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀ3-phenylpropionaldehydeꢀ(0.80ꢀmL,ꢀ0.82ꢀg,ꢀ6.0ꢀmmol,ꢀ1ꢀ
4
equiv),ꢀꢀallylꢀphenylꢀether ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(15ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ30%ꢀofꢀtheꢀproductꢀ(0.486ꢀg,ꢀ1.81ꢀmmol)ꢀasꢀaꢀ
-
1
1
colorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3372,ꢀ3026,ꢀ2921,ꢀ1667,ꢀ1595,ꢀ1493,ꢀ1226,ꢀ1047,ꢀ754,ꢀ692;ꢀ HꢀNMRꢀ
CDCl ,ꢀ400ꢀMHz):ꢀδꢀ7.33-7.26ꢀ(m,ꢀ4H),ꢀ7.21-7.18ꢀ(m,ꢀ3H),ꢀ7.08-7.03ꢀ(m,ꢀ1H),ꢀ7.01-6.98ꢀ(m,ꢀ2H),ꢀ6.52ꢀ(dt,ꢀJꢀ
ꢀ6.2,ꢀ1.3ꢀHz,ꢀ1H),ꢀ4.89ꢀ(dt,ꢀJꢀ=ꢀ7.6,ꢀ6.2ꢀHz,ꢀ1H),ꢀ3.78-3.71ꢀ(m,ꢀ1H),ꢀ2.86-2.67ꢀ(m,ꢀ2H),ꢀ2.46-2.42ꢀ(m,ꢀ2H),ꢀ
(
3
=
1
1
1
3
.86-1.80ꢀ(m,ꢀ2H),ꢀ1.63ꢀ(d,ꢀJꢀ=ꢀ4.7ꢀHz,ꢀ1H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ157.3,ꢀ142.5,ꢀ142.2,ꢀ129.7,ꢀ128.5,ꢀ
ꢀ+ꢀ
28.4,ꢀ125.8,ꢀ122.8,ꢀ116.4,ꢀ108.0,ꢀ77.5,ꢀ77.1,ꢀ76.8,ꢀ70.9,ꢀ38.6,ꢀ32.2,ꢀ32.1;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C18
20 2
H O
+
Na] ꢀcalcdꢀ291.1356,ꢀfoundꢀ291.1356.ꢀ
ꢀ
(
Z)-4-isopropoxy-1-phenylbut-3-en-1-olꢀ (21):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ toꢀ theꢀ generalꢀ
procedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀꢀbenzaldehydeꢀ(2.00ꢀmL,ꢀ2.09ꢀg,ꢀ19.7ꢀmmol,ꢀ1ꢀequiv),ꢀallylꢀ
1
isopropylꢀ ether ꢀ (1.3ꢀ equiv),ꢀ andꢀ THFꢀ (55ꢀ mL).ꢀ ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ columnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ43%ꢀofꢀtheꢀproductꢀ(1.76ꢀg,ꢀ8.53ꢀmmol)ꢀasꢀaꢀ
-
1
colorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3398,ꢀ3030,ꢀ2973,ꢀ2930,ꢀ2877,ꢀ1662,ꢀ1493,ꢀ1383,ꢀ1338,ꢀ1104,ꢀ1049,ꢀ912,ꢀ
1
7
4
43,ꢀ700;ꢀ HꢀNMRꢀ(CDCl
.74ꢀ(m,ꢀ1H),ꢀ4.39ꢀ(dt,ꢀJꢀ=ꢀ7.4,ꢀ6.4ꢀHz,ꢀ1H),ꢀ3.92ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1H),ꢀ2.65-2.47ꢀ(m,ꢀ3H),ꢀ1.22ꢀ(m,ꢀ6H);ꢀ Cꢀ
,ꢀ100ꢀMHz):ꢀδꢀ146.0,ꢀ144.5,ꢀ128.2,ꢀ127.2,ꢀ101.7,ꢀ74.3,ꢀ74.1,ꢀ34.4,ꢀ22.4ꢀ(2ꢀC);ꢀHRMSꢀ(ES)ꢀcalcdꢀ
3
,ꢀ400ꢀMHz):ꢀδꢀ7.39-7.31ꢀ(m,ꢀ4H),ꢀ7.27-7.23ꢀ(m,ꢀ1H),ꢀ6.13ꢀ(dt,ꢀJꢀ=ꢀ6.3,ꢀ1.2ꢀHz,ꢀ1H),ꢀ
1
3
NMRꢀ(CDCl
3
+
forꢀ[C13H O ꢀ+ꢀNa] ꢀcalcdꢀ229.1199,ꢀfoundꢀ229.1209.ꢀ
18 2
S14ꢀ
ꢀ

ꢀ
(
Z)-1-(2,5-dimethoxyphenyl)-4-isopropoxybut-3-en-1-olꢀ(22):ꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀ
theꢀgeneralꢀprocedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀꢀ2,5-dimethoxybenzaldehydeꢀ(2.64ꢀg,ꢀ15.9ꢀmmol,ꢀ
1
1
ꢀequiv),ꢀallylꢀisopropylꢀether ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(50ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ5ꢀ-ꢀ10%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ35%ꢀofꢀtheꢀproductꢀ(1.47ꢀg,ꢀ5.53ꢀmmol)ꢀasꢀaꢀ
-
1
1
paleꢀyellowꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3448,ꢀ3039,ꢀ2972,ꢀ2936,ꢀ2833,ꢀ1662,ꢀ1590,ꢀ1497,ꢀ1216,ꢀ1048;ꢀ HꢀNMRꢀ
CDCl ,ꢀ400ꢀMHz):ꢀδꢀ7.00ꢀ(d,ꢀJꢀ=ꢀ3.0ꢀHz,ꢀ1H),ꢀ6.80-7.72ꢀ(m,ꢀ2H),ꢀ6.11ꢀ(dt,ꢀJꢀ=ꢀ6.3,ꢀ1.2ꢀHz,ꢀ1H),ꢀ4.92ꢀ(dt,ꢀJꢀ=ꢀ
.4,ꢀ5.4ꢀHz,ꢀ1H),ꢀ4.42ꢀ(m,ꢀ1H),ꢀ3.91ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1H),ꢀ3.80ꢀ(s,ꢀ3H),ꢀ3.79ꢀ(s,ꢀ3ꢀH),ꢀ2.89ꢀ(d,ꢀJꢀ=ꢀ5.5ꢀHz,ꢀ1ꢀH),ꢀ
(
3
7
2
7
1
3
.62-2.49ꢀ(m,ꢀ2ꢀH),ꢀ1.21ꢀ(m,ꢀ6H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ153.6,ꢀ150.6,ꢀ145.6,ꢀ133.6,ꢀ102.4,ꢀ74.1,ꢀ
+
0.1,ꢀ55.8,ꢀ55.7,ꢀ32.2,ꢀ22.4ꢀ(2ꢀC);ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C15
22 4
H O ꢀ+ꢀNa] ꢀcalcdꢀ289.1409,ꢀfoundꢀ289.1410.ꢀ
ꢀ
Z)-4-isopropoxy-1-(thiophen-2-yl)but-3-en-1-olꢀ (23):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ toꢀ theꢀ
(
generalꢀprocedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀꢀ2-thiophenecarboxaldehydeꢀ(1.00ꢀmL,ꢀ1.20ꢀg,ꢀ10.7ꢀ
1
mmol,ꢀ1ꢀequiv),ꢀallylꢀisopropylꢀether ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(50ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀ
columnꢀchromatographyꢀ(silicaꢀgel,ꢀ10ꢀ-ꢀ15%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ36%ꢀofꢀtheꢀproductꢀ(0.813ꢀg,ꢀ3.83ꢀ
-
1
mmol)ꢀasꢀaꢀpaleꢀyellowꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3414,ꢀ3041,ꢀ2973,ꢀ2930,ꢀ1662,ꢀ1452,ꢀ1384,ꢀ1372,ꢀ1339,ꢀ
1
1
249,ꢀ1103,ꢀ1041,ꢀ698;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.22ꢀ(dd,ꢀJꢀ=ꢀ4.9,ꢀ1.4ꢀHz,ꢀ1H),ꢀ6.99-6.95ꢀ(m,ꢀ2H),ꢀ6.15ꢀ
(
dt,ꢀJꢀ=ꢀ6.4,ꢀ1.3ꢀHz,ꢀ1H),ꢀ5.01-4.97ꢀ(m,ꢀ1H),ꢀ4.43ꢀ(dt,ꢀJꢀ=ꢀ7.4,ꢀ6.4ꢀHz,ꢀ1H),ꢀ3.94ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1H),ꢀ1.24-
1
3
1
2
.22ꢀ(m,ꢀ6H);ꢀ CꢀNMRꢀ(CDCl
2.4;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C11
3
,ꢀ100ꢀMHz):ꢀδꢀ148.6,ꢀ146.2,ꢀ126.5,ꢀ124.2,ꢀ123.3,ꢀ101.1,ꢀ74.4,ꢀ70.3,ꢀ34.4,ꢀ
+
H
16
O
2
Sꢀ+ꢀNa] ꢀcalcdꢀ235.0763,ꢀfoundꢀ235.0771.ꢀ
ꢀ
(
Z)-8-((tert-butyldimethylsilyl)oxy)-1-isopropoxyoct-1-en-4-olꢀ (24):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ
accordingꢀ toꢀ theꢀ generalꢀ procedureꢀ forꢀ 4-hydroxyꢀ enolꢀ ethersꢀ usingꢀ 5-((tert-
butyldimethylsilyl)oxy)pentanal ꢀ(1.50ꢀg,ꢀ6.90ꢀmmol,ꢀ1ꢀequiv),ꢀallylꢀisopropylꢀether ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ
20ꢀmL).ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ3ꢀ-ꢀ5%ꢀEtOAc/hexanes)ꢀ
ꢀ
6
1
(
-
1
toꢀgiveꢀ33%ꢀofꢀtheꢀproductꢀ(0.721ꢀg,ꢀ2.27ꢀmmol)ꢀasꢀaꢀcolorlessꢀoil.ꢀꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3409,ꢀ3037,ꢀ2930,ꢀ
1
2
858,ꢀ1662,ꢀ1482,ꢀ1384,ꢀ1337,ꢀ1254,ꢀ1101,ꢀ835,ꢀ775;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ6.12ꢀ(dt,ꢀJꢀ=ꢀ6.3,ꢀ1.2ꢀ
Hz,ꢀ1H),ꢀ4.43ꢀ(dt,ꢀJꢀ=ꢀ7.6,ꢀ6.4ꢀHz,ꢀ1H),ꢀ3.92ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1H),ꢀ3.63-3.60ꢀ(m,ꢀ3H),ꢀ2.25-2.21ꢀ(m,ꢀ2H),ꢀ2.01ꢀ
1
3
(
d,ꢀJꢀ=ꢀ4.1ꢀHz,ꢀ1H),ꢀ1.22ꢀ(d,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ6H),ꢀ0.89ꢀ(s,ꢀ9H),ꢀ0.04ꢀ(s,ꢀ6H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ145.6,ꢀ
Siꢀ+ꢀ
1
02.1,ꢀ74.1,ꢀ71.7,ꢀ63.2,ꢀ36.5,ꢀ32.8,ꢀ32.1,ꢀ25.9,ꢀ22.3,ꢀ22.0,ꢀ18.3,ꢀ-5.3;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C17H O
36 3
+
Na] ꢀcalcdꢀ339.2326,ꢀfoundꢀ339.2334.ꢀ
S15ꢀ
ꢀ

ꢀ
(
Z)-3-(3-isopropoxallyl)-2,2,5,5-tetramethyltetrahydrofuran-3-olꢀ (27):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ
accordingꢀtoꢀtheꢀgeneralꢀprocedureꢀforꢀ4-hydroxyꢀenolꢀethersꢀusingꢀdihydro-2,2,5,5-tetramethyl-3(2H)-
1
furanoneꢀ(3.10ꢀmL,ꢀ2.87ꢀg,ꢀ20.2ꢀmmol,ꢀ1ꢀequiv),ꢀallylꢀisopropylꢀether ꢀ(1.3ꢀequiv),ꢀandꢀTHFꢀ(75ꢀmL).ꢀꢀTheꢀ
crudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ10ꢀ-ꢀ20%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ23%ꢀ
ofꢀtheꢀproductꢀ(1.13ꢀg,ꢀ4.66ꢀmmol)ꢀasꢀaꢀcolorlessꢀoilꢀwhichꢀsolidifiedꢀtoꢀaꢀwhiteꢀsolidꢀuponꢀstorageꢀinꢀ
-
1
1
freezer.ꢀꢀꢀFTIRꢀ(KBr,ꢀcm ):ꢀ3402,ꢀ2974,ꢀ1657,ꢀ1377,ꢀ1233,ꢀ1110,ꢀ1041,ꢀ982,ꢀ760;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀ
MHz):ꢀδꢀ6.16ꢀ(dt,ꢀJꢀ=ꢀ6.4,ꢀ1.2ꢀHz,ꢀ1H),ꢀ4.46ꢀ(dt,ꢀJꢀ=ꢀ7.7,ꢀ6.4ꢀHz,ꢀ1H),ꢀ3.94ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1H),ꢀ2.36-2.26ꢀ(m,ꢀ
2
3
H),ꢀ2.18ꢀ(brꢀs,ꢀ1H),ꢀ2.01ꢀ(m,ꢀ2H),ꢀ1.35ꢀ(s,ꢀ3H),ꢀ1.29ꢀ(s,ꢀ3H),ꢀ1.25ꢀ(s,ꢀ3H),ꢀ1.23ꢀ(d,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ6H),ꢀ1.20ꢀ(s,ꢀ
1
3
3
H);ꢀ CꢀNMRꢀ(CDCl ,ꢀ100ꢀMHz):ꢀδꢀ146.1,ꢀ100.8,ꢀ85.4,ꢀ84.2,ꢀ77.6,ꢀ50.4,ꢀ31.6,ꢀ31.0,ꢀ30.8,ꢀ26.9,ꢀ23.3,ꢀ22.4;ꢀ
+
26 3
HRMSꢀ(ES)ꢀcalcdꢀforꢀ[C14H O ꢀ+ꢀNa] ꢀcalcdꢀ265.1773,ꢀfoundꢀ265.1774.ꢀ
ꢀ
Generalꢀ procedureꢀ forꢀ theꢀ preparationꢀ ofꢀ furans:ꢀ ꢀ Toꢀ aꢀ stirredꢀ solutionꢀ ofꢀ Pd(OAc)
mmol,ꢀ0.025ꢀequiv),ꢀPPh ꢀ(26.3ꢀmg,ꢀ0.10ꢀmmol,ꢀ0.10ꢀequiv),ꢀp-benzoquinoneꢀ(119ꢀmg;ꢀ1.10ꢀmmol,ꢀ1.1ꢀ
equiv),ꢀandꢀAcOHꢀ(60ꢀμL,ꢀ1.0ꢀmmol,ꢀ1.0ꢀequiv)ꢀinꢀCH Cl ꢀ(1ꢀmL)ꢀwasꢀaddedꢀ4-hydroxyꢀenolꢀetherꢀ(1.0ꢀ
mmol,ꢀ1.0ꢀequiv).ꢀꢀTheꢀsolutionꢀwasꢀstirredꢀatꢀ24ꢀ⁰Cꢀforꢀ2ꢀ–ꢀ6ꢀh.ꢀꢀTheꢀreactionꢀmixtureꢀwasꢀthenꢀdilutedꢀ
withꢀCH Cl ꢀ(15ꢀmL)ꢀandꢀvigorouslyꢀstirredꢀwithꢀ2ꢀMꢀHCl(aq)ꢀ(10ꢀmL)ꢀforꢀ10ꢀminꢀ–ꢀ2ꢀh.ꢀꢀTheꢀorganicꢀlayerꢀ
wasꢀseparatedꢀandꢀtheꢀaqueousꢀlayerꢀwasꢀextractedꢀwithꢀCH Cl ꢀ(10ꢀmLꢀxꢀ3),ꢀtheꢀcombinedꢀorganicꢀlayersꢀ
wereꢀ driedꢀ overꢀ Na SO ,ꢀ decanted,ꢀ concentratedꢀ underꢀ reducedꢀ pressure,ꢀ andꢀ purifiedꢀ byꢀ columnꢀ
chromatographyꢀonꢀsilicaꢀgelꢀ(EtOAc/hexane)ꢀtoꢀaffordꢀpureꢀfuran.ꢀ
2
ꢀ (5.6ꢀ mg,ꢀ 0.025ꢀ
3
2
2
2
2
2
2
2
4
ꢀ
2
-phenethylfuranꢀ(20):ꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀgeneralꢀprocedureꢀforꢀfuransꢀusingꢀ
(
Z)-6-isopropoxy-1-phenylhex-5-en-3-olꢀ(235ꢀmg,ꢀ1.00ꢀmmol),ꢀandꢀstirringꢀforꢀ2ꢀh,ꢀthenꢀstirredꢀwithꢀ2ꢀMꢀ
HCl(aq)ꢀ forꢀ 10ꢀ min.ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ columnꢀ chromatographyꢀ (silicaꢀ gel,ꢀ 1%ꢀ
EtOAc/hexanes)ꢀ toꢀ giveꢀ 82%ꢀ ofꢀ theꢀ productꢀ (142ꢀ mg,ꢀ 0.825ꢀ mmol)ꢀ asꢀ aꢀ colorlessꢀ oil.ꢀ ꢀ Thisꢀ productꢀ
1
9
-1
spectroscopicallyꢀmatchedꢀthatꢀofꢀtheꢀknownꢀcompound. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3062,ꢀ3027,ꢀ2927,ꢀ2860,ꢀ
1
1
1
1
599,ꢀ1506,ꢀ1453,ꢀ1148,ꢀ1011,ꢀ923,ꢀ799;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.32-7.17ꢀ(m,ꢀ6H),ꢀ6.27ꢀ(dd,ꢀJꢀ=ꢀ3.1,ꢀ
1
3
.9ꢀHz,ꢀ1H),ꢀ5.96ꢀ(dd,ꢀJꢀ=ꢀ3.1,ꢀ0.7ꢀHz,ꢀ1H),ꢀ2.94ꢀ(m,ꢀ4H);ꢀ CꢀNMRꢀ(CDCl
28.5,ꢀ126.2,ꢀ110.2,ꢀ105.3,ꢀ34.5,ꢀ30.0.ꢀ
3
,ꢀ100ꢀMHz):ꢀ155.5,ꢀ141.3,ꢀ141.0,ꢀ
S16ꢀ
ꢀ

ꢀ
2
-Phenylfuranꢀ(21a):ꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀgeneralꢀprocedureꢀforꢀfuransꢀusingꢀ
(
Z)-4-isopropoxy-1-phenylbut-3-en-1-olꢀ(207ꢀmg,ꢀ1.00ꢀmmol),ꢀandꢀstirringꢀforꢀ2ꢀh,ꢀthenꢀstirredꢀwithꢀ2ꢀMꢀ
HCl(aq)ꢀ forꢀ 0.5ꢀ h.ꢀ ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ columnꢀ chromatographyꢀ (silicaꢀ gel,ꢀ 1%ꢀ
EtOAc/hexanes)ꢀ toꢀ giveꢀ 76%ꢀ ofꢀ theꢀ productꢀ (109ꢀ mg,ꢀ 0.756ꢀ mmol)ꢀ asꢀ aꢀ colorlessꢀ oil.ꢀ ꢀ Thisꢀ productꢀ
2
0
-1
spectroscopicallyꢀmatchedꢀthatꢀofꢀtheꢀknownꢀcompound. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3116,ꢀ3073,ꢀ1949,ꢀ1877,ꢀ
1
1
1
1
3
804,ꢀ1478,ꢀ1009,ꢀ759;ꢀ HꢀNMRꢀ(CDCl ,ꢀ400ꢀMHz):ꢀδꢀ7.67ꢀ(m,ꢀ2H),ꢀ7.47ꢀ(m,ꢀ1H),ꢀ7.38ꢀ(m,ꢀ2H),ꢀ7.25ꢀ(m,ꢀ
1
3
H),ꢀ6.65ꢀ(m,ꢀ1H),ꢀ6.47ꢀ(m,ꢀ1H);ꢀ CꢀNMRꢀ(CDCl
11.6,ꢀ105.0.ꢀ
3
,ꢀ100ꢀMHz):ꢀ154.0,ꢀ142.1,ꢀ130.9,ꢀ128.7,ꢀ127.3,ꢀ123.8,ꢀ
ꢀ
-(2,5-Dimethoxyphenyl)furanꢀ(22a):ꢀThisꢀreactionꢀwasꢀperformedꢀaccordingꢀtoꢀtheꢀgeneralꢀprocedureꢀ
2
forꢀ furansꢀ usingꢀ (Z)-1-(2,5-dimethoxyphenyl)-4-isopropoxybut-3-en-1-olꢀ (267ꢀ mg,ꢀ 1.00ꢀ mmol),ꢀ andꢀ
stirringꢀ forꢀ 2ꢀ h,ꢀ thenꢀ stirredꢀ withꢀ 2ꢀ Mꢀ HCl(aq)ꢀ forꢀ 0.5ꢀ h.ꢀ ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ columnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ3%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ91%ꢀofꢀtheꢀproductꢀ(186ꢀmg,ꢀ0.911ꢀmmol)ꢀasꢀaꢀ
-
1
colorlessꢀoil.ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3145,ꢀ3117,ꢀ2998,ꢀ2906,ꢀ2833,ꢀ2067,ꢀ1611,ꢀ1573,ꢀ1499,ꢀ1221,ꢀ1051,ꢀ739;ꢀ
1
HꢀNMRꢀ(CDCl
H),ꢀ6.91-6.88ꢀ(m,ꢀ1H),ꢀ6.82-6.79ꢀ(m,ꢀ1H),ꢀ6.51ꢀ(dd,ꢀJꢀ=ꢀ3.4,ꢀ1.8ꢀHz,ꢀ1H,ꢀ3.89ꢀ(s,ꢀ3H),ꢀ3.84ꢀ(s,ꢀ3H);ꢀ CꢀNMRꢀ
CDCl ,ꢀ 100ꢀ MHz):ꢀ δꢀ 153.8,ꢀ 150.1,ꢀ 149.8,ꢀ 141.2,ꢀ 120.6,ꢀ 113.4,ꢀ 112.4,ꢀ 111.8,ꢀ 111.1,ꢀ 110.2,ꢀ 55.9,ꢀ 55.8;ꢀ
HRMSꢀ(ES)ꢀcalcdꢀforꢀ[C12
3
,ꢀ400ꢀMHz):ꢀδꢀ7.48ꢀ(dd,ꢀJꢀ=ꢀ1.8,ꢀ0.8ꢀHz,ꢀ1H),ꢀ7.45ꢀ(d,ꢀJꢀ=ꢀ3.1ꢀHz,ꢀ1H),ꢀ7.00ꢀ(dd,ꢀJꢀ=ꢀ3.3,ꢀ0.8ꢀHz,ꢀ
1
3
1
(
3
+
12 3
H O ꢀ+ꢀNa] ꢀcalcdꢀ227.0679,ꢀfoundꢀ227.0684.ꢀ
ꢀ
-(2-thienyl)furanꢀ (23a):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ toꢀ theꢀ generalꢀ procedureꢀ forꢀ furansꢀ
2
usingꢀ (Z)-4-isopropoxy-1-(thiophen-2-yl)but-3-en-1-olꢀ (212ꢀ mg,ꢀ 1.00ꢀ mmol),ꢀ andꢀ stirringꢀ forꢀ 2ꢀ h,ꢀ thenꢀ
stirredꢀwithꢀ2ꢀMꢀHCl(aq)ꢀforꢀ2ꢀh.ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ
1
%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ72%ꢀofꢀtheꢀproductꢀ(108ꢀmg,ꢀ0.719ꢀmmol)ꢀasꢀaꢀpaleꢀyellowꢀoil.ꢀꢀThisꢀproductꢀ
2
0
-1
spectroscopicallyꢀmatchedꢀthatꢀofꢀtheꢀknownꢀcompound. ꢀꢀFTIRꢀ(film,ꢀcm ):ꢀ3110,ꢀ1589,ꢀ1521,ꢀ1483,ꢀ
1
1
7
1
3
424,ꢀ1016,ꢀ978,ꢀ844,ꢀ731,ꢀ696;ꢀ HꢀNMRꢀ(CDCl ,ꢀ400ꢀMHz):ꢀδꢀ7.8ꢀ(m,ꢀ1H),ꢀ7.23ꢀ(dd,ꢀJꢀ=ꢀ4.0,ꢀ1.1ꢀHz,ꢀ1H),ꢀ
1
3
.19ꢀ(m,ꢀ1H),ꢀ7.01ꢀ(m,ꢀ1H),ꢀ7.01ꢀ(m,ꢀ1H),ꢀ6.48ꢀ(m,ꢀ1H),ꢀ6.41ꢀ(m,ꢀ1H);ꢀ CꢀNMRꢀ(CDCl
41.6,ꢀ133.8,ꢀ127.6,ꢀ124.1,ꢀ122.6,ꢀ111.7,ꢀ105.0.ꢀ
3
,ꢀ100ꢀMHz):ꢀ149.6,ꢀ
ꢀ
S17ꢀ
ꢀ

Tert-butyl(4-(furan-2-yl)butoxy)dimethylsilaneꢀ (24a):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ toꢀ theꢀ
generalꢀ procedureꢀ forꢀ furansꢀ usingꢀ (Z)-8-((tert-butyldimethylsilyl)oxy)-1-isopropoxyoct-1-en-4-olꢀ (317ꢀ
mg,ꢀ1.00ꢀmmol),ꢀandꢀstirringꢀforꢀ6ꢀh,ꢀthenꢀstirredꢀwithꢀ2ꢀMꢀHCl(aq)ꢀforꢀ1ꢀh.ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀ
byꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ3%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ78%ꢀofꢀtheꢀproductꢀ(199ꢀmg,ꢀ0.785ꢀ
2
1
mmol)ꢀasꢀaꢀcolorlessꢀoil.ꢀꢀThisꢀproductꢀspectroscopicallyꢀmatchedꢀthatꢀofꢀtheꢀknownꢀcompound. ꢀꢀFTIRꢀ
-
1
1
(
film,ꢀcm ):ꢀ2952,ꢀ2929,ꢀ2893,ꢀ2857,ꢀ1596,ꢀ1508,ꢀ1471,ꢀ1387,ꢀ1255,ꢀ1104,ꢀ837,ꢀ775;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀ
MHz):ꢀδꢀ7.30ꢀ(dd,ꢀJꢀ=ꢀ1.8,ꢀ0.8ꢀHz,ꢀ1H),ꢀ6.28ꢀ(dd,ꢀJꢀ=ꢀ3.1,ꢀ1.9ꢀHz,ꢀ1H),ꢀ5.98ꢀ(m,ꢀ1H),ꢀ3.63ꢀ(t,ꢀJꢀ=ꢀ6.4ꢀHz,ꢀ2H),ꢀ
1
3
2
1
.64ꢀ(t,ꢀJꢀ=ꢀ7.3ꢀHz,ꢀ2H),ꢀ1.74-1.66ꢀ(m,ꢀ2H),ꢀ2.00-1.53ꢀ(m,ꢀ2H),ꢀ0.90ꢀ(s,ꢀ9H),ꢀ0.50ꢀ(s,ꢀ6H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ
00ꢀ MHz):ꢀ 156.3,ꢀ 140.7,ꢀ 110.0,ꢀ 104.7,ꢀ 62.9,ꢀ 32.3,ꢀ 27.7,ꢀ 26.0,ꢀ 24.4,ꢀ 18.4,ꢀ -5.29;ꢀ HRMSꢀ (ES)ꢀ calcdꢀ forꢀ
+
14 26 2
[C H O Siꢀ+ꢀNa] ꢀcalcdꢀ277.1594,ꢀfoundꢀ227.1598.ꢀ
ꢀ
Generalꢀprocedureꢀforꢀtheꢀpreparationꢀofꢀ2,5-dihydrofurans:ꢀꢀToꢀaꢀstirredꢀsolutionꢀofꢀPd(OAc)
2
ꢀ(5.6ꢀmg,ꢀ
ꢀ(26.3ꢀmg,ꢀ0.10ꢀmmol,ꢀ0.10ꢀequiv),ꢀp-benzoquinoneꢀ(119ꢀmg;ꢀ1.10ꢀmmol,ꢀ
.1ꢀequiv),ꢀandꢀAcOHꢀ(60ꢀμL,ꢀ1.0ꢀmmol,ꢀ1.0ꢀequiv)ꢀinꢀCH Cl ꢀ(1ꢀmL)ꢀwasꢀaddedꢀ4-hydroxyꢀenolꢀetherꢀ(1.0ꢀ
0
1
.025ꢀmmol,ꢀ0.025ꢀequiv),ꢀPPh
3
2
2
mmol,ꢀ1.0ꢀequiv).ꢀꢀTheꢀsolutionꢀwasꢀstirredꢀatꢀ24ꢀ⁰Cꢀforꢀ1ꢀ-ꢀ17ꢀh.ꢀꢀTheꢀreactionꢀmixtureꢀwasꢀthenꢀdilutedꢀ
withꢀCH Cl ꢀ(15ꢀmL)ꢀandꢀwashedꢀwithꢀsat.ꢀNaHSO3(aq)ꢀ(10ꢀmL).ꢀꢀTheꢀorganicꢀlayerꢀwasꢀseparatedꢀandꢀtheꢀ
aqueousꢀ layerꢀ wasꢀ extractedꢀ withꢀ CH Cl ꢀ (10ꢀ mLꢀ xꢀ 3),ꢀ theꢀ combinedꢀ organicꢀ layersꢀ wereꢀ driedꢀ overꢀ
Na SO ,ꢀdecanted,ꢀconcentratedꢀunderꢀreducedꢀpressure,ꢀandꢀpurifiedꢀbyꢀcolumnꢀchromatographyꢀonꢀ
silicaꢀgelꢀ(EtOAc/hexane)ꢀtoꢀaffordꢀpureꢀ2,5-dihydrofuran.ꢀ
2
2
2
2
2
4
ꢀ
2
-(2,5-dimethoxyphenyl)-5-isopropoxy-2,5-dihydrofuranꢀ (25):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ
toꢀ theꢀ generalꢀ procedureꢀ forꢀ 2,5-dihydrofuransꢀ usingꢀ (Z)-1-(2,5-dimethoxyphenyl)-4-isopropoxybut-3-
en-1-olꢀ (0.266ꢀ g,ꢀ 1.00ꢀ mmol),ꢀ andꢀ stirringꢀ forꢀ 1ꢀ h.ꢀ ꢀ Theꢀ crudeꢀ productꢀ wasꢀ purifiedꢀ byꢀ columnꢀ
chromatographyꢀ(silicaꢀgel,ꢀ3%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ85%ꢀofꢀtheꢀproductꢀ(225ꢀmg,ꢀ0.852ꢀmmol)ꢀasꢀaꢀ
paleꢀyellowꢀoil.ꢀꢀTheꢀproductꢀwasꢀisolatedꢀasꢀaꢀ1:1ꢀmixtureꢀofꢀdiastereomers.ꢀꢀFTIRꢀ(film,ꢀcm-1):ꢀ2969,ꢀ
1
2
833,ꢀ1496,ꢀ1466,ꢀ1216,ꢀ1041,ꢀ805;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.17ꢀ(d,ꢀJꢀ=ꢀ2.6ꢀHz,ꢀ1H),ꢀ6.91ꢀ(d,ꢀJꢀ=ꢀ2.9ꢀ
Hz,ꢀ1H),ꢀ6.81-6.73ꢀ(m,ꢀ2H),ꢀ6.29ꢀ(dt,ꢀJꢀ=ꢀ5.9,ꢀ1.2ꢀHz,ꢀ0.5H),ꢀ6.25ꢀ(dt,ꢀJꢀ=ꢀ5.9,ꢀ1.4ꢀHz,ꢀ0.5H),ꢀ6.23ꢀ-6.21ꢀ(m,ꢀ
.5H),ꢀ6.16-6.15ꢀ(m,ꢀ0.5H),ꢀ6.06ꢀ(m,ꢀ0.5H),ꢀ6.02ꢀ(m,ꢀ0.5H),ꢀ5.82-5.80ꢀ(m,ꢀ0.5H),ꢀ5.76-5.74ꢀ(m,ꢀ0.5H),ꢀ4.12ꢀ
sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ0.5H),ꢀ4.04ꢀ(sep,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ0.5H),ꢀ3.80ꢀ(m,ꢀ3H),ꢀ3.76ꢀ(m,ꢀ3H),ꢀ1.34ꢀ(d,ꢀJꢀ=ꢀ6.2,ꢀ1.5ꢀHz,ꢀ
0
(
1
3
1
1
.5H),ꢀ1.27ꢀ(d,ꢀJꢀ=ꢀ6.2,ꢀ1.5ꢀHz,ꢀ1.5H),ꢀ1.24ꢀ(m,ꢀ3H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ154.0,ꢀ153.9,ꢀ150.6,ꢀ
49.9,ꢀ135.5,ꢀ134.9,ꢀ130.6,ꢀ130.0,ꢀ125.9,ꢀ125.2,ꢀ113.7,ꢀ112.9,ꢀ112.6,ꢀ112.4,ꢀ111.4,ꢀ111.2,ꢀ107.6,ꢀ107.5,ꢀ
S18ꢀ
ꢀ

+
8
2.2,ꢀ81.2,ꢀ70.9,ꢀ70.0,ꢀ56.0,ꢀ55.9,ꢀ55.7ꢀ(2ꢀC),ꢀ24.0,ꢀ23.8,ꢀ22.6,ꢀ22.4;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C15
20 4
H O ꢀ+ꢀNa] ꢀ
calcdꢀ287.1254,ꢀfoundꢀ287.1272.ꢀꢀ
ꢀ
2
-Isopropoxy-5-(thiophen-2-yl)-2,5-dihydrofuranꢀ (26):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ accordingꢀ toꢀ theꢀ
generalꢀprocedureꢀforꢀ2,5-dihydrofuransꢀusingꢀ(Z)-4-isopropoxy-1-(thiophen-2-yl)but-3-en-1-olꢀ(0.212ꢀg,ꢀ
1
3
.00ꢀmmol),ꢀandꢀstirringꢀforꢀ1.5ꢀh.ꢀꢀTheꢀcrudeꢀproductꢀwasꢀpurifiedꢀbyꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ
%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ91%ꢀofꢀtheꢀproductꢀ(191ꢀmg,ꢀ0.907ꢀmmol)ꢀasꢀaꢀpaleꢀyellowꢀoil.ꢀꢀTheꢀproductꢀ
wasꢀisolatedꢀasꢀaꢀ1:1ꢀmixtureꢀofꢀdiastereomers.ꢀꢀFTIRꢀ(film,ꢀcm-1):ꢀ3087,ꢀ2971,ꢀ2891,ꢀ2244,ꢀ1624,ꢀ1465,ꢀ
1
1
=
1
1
2
438,ꢀ1378,ꢀ1343,ꢀ1310;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ7.24ꢀ(m,ꢀ1H),ꢀ7.00ꢀ(m,ꢀ1H),ꢀ6.93ꢀ(m,ꢀ1H),ꢀ6.21ꢀ(dt,ꢀJꢀ
ꢀ5.9,ꢀ1.2ꢀHz,ꢀ0.5H),ꢀ6.18ꢀ(m,ꢀ0.5H),ꢀ6.12(m,ꢀ0.5H),ꢀ6.07ꢀ(m,ꢀ0.5H),ꢀ5.93ꢀ(m,ꢀ1H),ꢀ5.89(m,ꢀ1H),ꢀ4.00ꢀ(m,ꢀ
1
3
3
H),ꢀ1.26ꢀ(d,ꢀJꢀ=ꢀ6.2ꢀHz,ꢀ1.5H),ꢀ1.20ꢀ(m,ꢀ4.5H);ꢀ CꢀNMRꢀ(CDCl ,ꢀ100ꢀMHz):ꢀδꢀ145.0,ꢀ144.1,ꢀ134.8,ꢀ134.3,ꢀ
27.8,ꢀ127.2,ꢀ126.8,ꢀ126.5,ꢀ125.9,ꢀ125.7,ꢀ125.3,ꢀ125.1,ꢀ107.1,ꢀ106.7,ꢀ82.1,ꢀ81.7,ꢀ70.5,ꢀ70.2,ꢀ23.8,ꢀ23.7,ꢀ
+
2.4,ꢀ22.1;ꢀHRMSꢀ(ES)ꢀcalcdꢀforꢀ[C11
H
14
O
2
Sꢀ+ꢀNa] ꢀcalcdꢀ233.0607,ꢀfoundꢀ233.0605.ꢀ
ꢀ
-Isopropoxy-6,6,8,8-tetramethyl-1,7-dioxaspiro[4.4]non-3-eneꢀ (27a):ꢀ Thisꢀ reactionꢀ wasꢀ performedꢀ
2
accordingꢀ toꢀ theꢀ generalꢀ procedureꢀ forꢀ 2,5-dihydrofuransꢀ usingꢀ (Z)-3-(3-isopropoxallyl)-2,2,5,5-
tetramethyltetrahydrofuran-3-olꢀ (0.242ꢀ g,ꢀ 1.00ꢀ mmol),ꢀ andꢀ stirringꢀ forꢀ 17ꢀ h.ꢀ ꢀ Theꢀ crudeꢀ productꢀ wasꢀ
purifiedꢀbyꢀcolumnꢀchromatographyꢀ(silicaꢀgel,ꢀ4%ꢀEtOAc/hexanes)ꢀtoꢀgiveꢀ77%ꢀofꢀtheꢀproductꢀ(185ꢀmg,ꢀ
0
.770ꢀ mmol)ꢀ asꢀ aꢀ colorlessꢀ oil.ꢀ ꢀ Theꢀ productꢀ wasꢀ isolatedꢀ asꢀ aꢀ 3:1ꢀ mixtureꢀ ofꢀ diastereomers,ꢀ theꢀ
assignmentꢀ ofꢀ diastereomersꢀ wasꢀ notꢀ clearꢀ fromꢀ NOESYꢀ experiment.ꢀ ꢀ FTIRꢀ (film,ꢀ cm-1):ꢀ 2971,ꢀ 2931,ꢀ
1
1
465,ꢀ1378,ꢀ1066,ꢀ1025,ꢀ1006,ꢀ742;ꢀ HꢀNMRꢀ(CDCl
3
,ꢀ400ꢀMHz):ꢀδꢀ6.03-6.00ꢀ(m,ꢀ1H),ꢀ5.86ꢀ(m,ꢀ1H),ꢀ5.84ꢀ
(
dd,ꢀJꢀ=ꢀ6.0,ꢀ1.0ꢀHz,ꢀ0.35H),ꢀ5.77ꢀ(dd,ꢀJꢀ=ꢀ5.9,ꢀ1.2ꢀHz,ꢀ0.65H),ꢀ4.07-3.95ꢀ(m,ꢀ1H),ꢀ2.33ꢀ(d,ꢀJꢀ=ꢀ13.4ꢀHz,ꢀ
0
1
.35H),ꢀ2.23ꢀ(d,ꢀJꢀ=ꢀ13.3ꢀHz,ꢀ0.65H),ꢀ2.03ꢀ(d,ꢀJꢀ=ꢀ13.4ꢀHz,ꢀ0.35H),ꢀ1.93ꢀ(d,ꢀJꢀ=ꢀ13.3ꢀHz,ꢀ0.65H),ꢀ1.38ꢀ(m,ꢀ3H),ꢀ
.32ꢀ(m,ꢀ3H),ꢀ1.31ꢀ(m,ꢀ2H),ꢀ1.25ꢀ(m,ꢀ1.65H),ꢀ1.24ꢀ(m,ꢀ3.35H),ꢀ1.20ꢀꢀ(m,ꢀ1.35H),ꢀ1.18-1.17ꢀ(m,ꢀ4.65H),ꢀ1.13ꢀ
1
3
(
m,ꢀ1H);ꢀ CꢀNMRꢀ(CDCl
3
,ꢀ100ꢀMHz):ꢀδꢀ134.3,ꢀ134.0,ꢀ128.2,ꢀ127.5,ꢀ106.7,ꢀ105.9,ꢀ100.4,ꢀ100.2,ꢀ85.3,ꢀ85.0,ꢀ
7
9.2,ꢀ78.6,ꢀ70.3,ꢀ70.1,ꢀ50.2,ꢀ49.9,ꢀ31.4,ꢀ31.3,ꢀ30.3,ꢀ29.9,ꢀ28.0,ꢀ27.6,ꢀ24.5,ꢀ23.8,ꢀ23.5,ꢀ22.9,ꢀ22.5,ꢀ21.9;ꢀ
+
HRMSꢀ(ES)ꢀcalcdꢀforꢀ[C14
24 3
H O ꢀ+ꢀNa] ꢀcalcdꢀ263.1618,ꢀfoundꢀ263.1609.ꢀꢀ
References:ꢀ
1
2
3
4
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