Enantiomerically pure acetals in organic synthesis. 1. Chromatographic separability of furanoside and pyranoside acetals derived from .alpha.-hydroxy esters

Mash, Eugene A.; Arterburn, Jeffrey B.; Fryling, J. A.; Mitchell, Susan H.

doi:10.1021/jo00003a034

Cited by 19 publications

(8 citation statements)

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“…colorless oil from 3-pentanone and (2R,3R)-pentanediol; same procedure as for (4R,5S)-1. EIMS m/z 144 (5), 143 (57), 128 (2), 114 (10), 87 (11), 86 (22), 75 (3), 70 (7), 69 (65), 58 (4), 57 (100), 56 (5), 55 (14), 45 (8), 43 (6), 42 (6), 41 (18), 39 (5); NMR data matched those reported earlier. 7 (4S,5S)-2,2,4-Triethyl-5-methyl-1,3-dioxolane, (4S,5S)-1:…”

Section: Methyl (R)-2-(tetrahydropyran-2-yloxy)propanoate (R)-supporting

confidence: 81%

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Structure Elucidation and Synthesis of Dioxolanes Emitted by Two Triatoma Species (Hemiptera: Reduviidae)

et al. 2011

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Volatiles from the metasternal glands of two species of true bugs of the Triatominae subfamily, Triatoma brasiliensis and Triatoma infestans, were analyzed by SPME-GC/MS. Two sets of new natural products were found: (4S,5S)- and (4R,5R)-2,2,4-triethyl-5-methyl-1,3-dioxolane (1) (major component) and (4S*,5S*)-2,4-diethyl-2,5-dimethyl-1,3-dioxolane (2) (trace component), (2R/S,4S,5S)- as well as (2R/S,4R,5R)-4-ethyl-5-methyl-2-(1-methylethyl)-1,3-dioxolane (3) (minor component), (2R/S,4S*,5S*)-4-ethyl-5-methyl-2-(1-methylpropyl)-1,3-dioxolane (4) (trace component), and (2R/S,4S*,5S*)-4-ethyl-5-methyl-2-(2-methylpropyl)-1,3-dioxolane (5) (trace component). Syntheses of optically active 1 and 3 were carried out by reacting pure enantiomers of 2,3-pentanediol with 3-pentanone or 2-methylpropanal. The preparation of pure stereoisomers of 2,3-pentanediol involved a novel key step for the synthesis of secondary alcohols: the reduction of a carboxylic ester by means of DIBAH and in situ alkylation of the intermediate by Grignard reaction at low temperature. Starting from the pure enantiomers of methyl lactate, all four stereoisomers of 2,3-pentanediol were synthesized and transformed to the corresponding isomers of 1 and 2. Relative configurations of the natural products and enantiomeric compositions of naturally occurring 1 and 2 were determined by comparison of their mass spectra and gas chromatographic retention times (co-injection) with those of authentic reference samples.

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Section: Methyl (R)-2-(tetrahydropyran-2-yloxy)propanoate (R)-supporting

confidence: 81%

“…EIMS m / z 129 (7), 101 (32), 88 (8), 87 (7), 85 (100), 71 (7), 67 (10), 59 (7), 57 (10), 56 (8), 55 (12), 45 (9), 43 (9), 41 (10). NMR data corresponded to published data. , …”

Section: Methodssupporting

confidence: 73%

Structure Elucidation and Synthesis of Dioxolanes Emitted by Two Triatoma Species (Hemiptera: Reduviidae)

et al. 2011

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“…42 Methyl (S)-lactate 2, diisobutylaluminum hydride (DIBAH, 1 M in hexanes), 1,4-diazabicyclo[2.2.2]octane (DABCO), pyridinium p-toluenesulfonate (PPTS), diphenylchlorophosphate, trifluoroacetic acid anhydride, BrCCl 3 , BEt 3 (1 M in hexane), (S)-a-methoxy-a-trifluoromethylphenylacetyl chloride, N(CH 3 ) 3 (4.2 M in EtOH) were obtained from commercial sources (Fluka, Aldrich and Merck) and were used as received. Methyl 2-(tetrahydropyran-2-yl)-oxypropanoat, 18 N-hydroxy-4-methylthiazole-2(3H)-thione 43 and the corresponding tetraalkylammmonium salt 21 were prepared according to literature procedures. Petroleum ether refers to the fraction boiling between 35 and 50°C.…”

Section: Resultsmentioning

confidence: 99%

“…The selective O-protection of methyl (S)-lactate 2 using 3,4-dihydro-2H-pyran and pyridinium p-toluenesulfonate (PPTS) in CH 2 Cl 2 provided (2S)-(2-tetrahydropyranyloxy)propanal (92%, not shown in Scheme 1) 18 which was treated with 1.5 equiv. of diisobutylaluminum hydride (DIBAH) in hexane/Et 2 O and subsequently with allyl magnesium bromide in Et 2 O (both steps at −78°C) to furnish 2-tetrahydropyranyloxy-5-hexen-3-ol 3 as a mixture of diastereomers (69% starting from 2, Scheme 1).…”

Section: Synthesis Of Alkoxyl Radical Precursorsmentioning

confidence: 99%

“…of methyl 2-(tetrahydropyran-2-yl)oxypropanoat 18 (1.18 g, 6.28 mmol) in dry Et 2 O (30 mL) was treated under argon at −78°C dropwise with a solution of DIBAH (9.4 mL, 1 M in hexanes). The reaction mixture was stirred for 30 min at −78°C and treated at this temperature dropwise with a solution of allyl magnesium bromide in Et 2 O prepared from magnesium turnings (336 mg, 13.8 mmol) and allyl bromide (1.52 g, 12.6 mmol) in dry Et 2 O (13 mL).…”

Section: -(Tetrahydropyran-2-yl)oxy-5-hexen-3-ol 3 a Solutionmentioning

confidence: 99%

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Synthesis of enantiopure (2R)-configured muscarine alkaloids via selective alkoxyl radical ring-closure reactions

Hartung

Kneuer

2003

Tetrahedron: Asymmetry

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Ethyl Mandelate

Bergbreiter¹

2001

Encyclopedia of Reagents for Organic Synthesis

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Enantiomerically pure acetals in organic synthesis. 1. Chromatographic separability of furanoside and pyranoside acetals derived from .alpha.-hydroxy esters

Cited by 19 publications

References 0 publications

Structure Elucidation and Synthesis of Dioxolanes Emitted by Two Triatoma Species (Hemiptera: Reduviidae)

Structure Elucidation and Synthesis of Dioxolanes Emitted by Two Triatoma Species (Hemiptera: Reduviidae)

Synthesis of enantiopure (2R)-configured muscarine alkaloids via selective alkoxyl radical ring-closure reactions

Ethyl Mandelate

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