The Protection of Hydroxyl Groups

Parham, William E.; Anderson, Elizabeth

doi:10.1021/ja01192a062

Cited by 135 publications

(59 citation statements)

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“…First, the diols 36a,b were transformed with 1 equiv. of 3,4-dihydro-2H-pyran into the monoprotected compounds 37a,b, respectively, in moderate yield [26] [27]. Synthesis of 37c was carried out starting from 34 that was protected to give 3,4,5,6-tetrahydro-2-(undec-10-enyloxy)-2H-pyran (35).…”

mentioning

confidence: 99%

Volatile Organic Compounds from Arctic Bacteria of the Cytophaga‐Flavobacterium‐Bacteroides Group: A Retrobiosynthetic Approach in Chemotaxonomic Investigations

Dickschat

Helmke

Schulz

2005

Chemistry & Biodiversity

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Volatile organic compounds emitted by different marine arctic strains of the Cytophaga-Flavobacterium-Bacteroides group were investigated by using a modified closed-loop stripping apparatus (CLSA). Seven of nine strains emitted volatiles, dominated by methyl ketones, in specific patterns. The methyl ketones were aliphatic saturated, or unsaturated, and comprised 12 to 18 C-atoms, sometimes with terminal Me branches. They were identified by GC/MS, retention-index calculations, derivatization with dimethyl disulfide for C=C bond location, and GC/FTIR to elucidate their uniform (Z)-configuration. The proposed structures of all methyl ketones were subsequently confirmed by synthesis, while the absolute configuration of chiral volatiles was elucidated by stereoselective synthesis. From retrobiosynthetic considerations, it was found that strain ARK10267 uses mainly valine, and strain ARK10063 mainly isoleucine for formation of starters for the ketone biosynthesis, which is correlated to fatty acid biosynthesis. Four strains (ARK10223, ARK10044, ARK10141, and ARK10146) use leucine. These separations are supported by phylogenetic affiliations based on 16S rRNA. Strain ARK10255b, in the course of this study found to be not a member of the Cytophaga-Flavobacterium-Bacteroides phylum, did not emit aliphatic ketones of medium chain length, but methionine-derived 4-(methylsulfanyl)butan-2-one and corresponding 4-(methylsulfanyl)butan-2-ol. Most of the compounds described have not been reported previously from nature.

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confidence: 99%

Volatile Organic Compounds from Arctic Bacteria of the Cytophaga‐Flavobacterium‐Bacteroides Group: A Retrobiosynthetic Approach in Chemotaxonomic Investigations

Dickschat

Helmke

Schulz

2005

Chemistry & Biodiversity

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“…In particular, dihydropyran (DHP) has been widely employed in the protection of alcohols and phenols to yield the corresponding THP ethers (Table 1), [1]- [2] especially due to the robust and unreactive nature of the resulting ethers under a variety of reaction conditions, notably towards strongly basic media, hydrides, acylating and alkylating agents. [3] Protection of alcohols and phenols with DHP has been widely examined in the past under a number of catalytic conditions, both homogeneous and heterogeneous.…”

Section: Introductionmentioning

confidence: 99%

Tetrahydropyranyl protection and deprotection of alcohols using a niobium-based Brønsted acid catalyst

et al. 2016

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Crites, CL.; Lima, FM.; Marín García, ML.; Netto Ferreira, JC.; Impellizzeri, S.; HallettTapley, GL.; Scaiano, JC. (2016) Abstract. Niobium phosphate (NbPO4) was used as a heterogeneous catalyst in the protection of a series of aliphatic alcohols as tetrahydropyranyl (THP) derivatives.Protection of primary alcohols using this material with strong Brønsted acid sites was achieved in good yields (75-94%), while moderate values were obtained in the protection of secondary and tertiary alcohols (50-84%), largely dependent on the steric hindrance in the proximity of the hydroxyl moiety. NbPO4 also catalyzed deprotection of THP ethers derived from primary alcohols and phenol with moderate yields (65-99%).2

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“…[5] The merits of acetal groups like THP and THF lie in their stability in the presence of various reagents such as basic media, alkyllithiums, metal hydrides, Grignard reagents, oxidative reagents, and alkylating or acylating reagents and under mild acidic conditions or heating, which promote cleavage. [6] Numerous methods have been reported for the tetrahydropyranylation of alcohols. [2] Generally, protic and Lewis acids are used as catalysts for this reaction.…”

Section: Introductionmentioning

confidence: 99%

Chemoenzymatic Synthesis of 3′‐O‐Acetal‐Protected 2′‐Deoxynucleosides as Building Blocks for Nucleic Acid Chemistry

et al. 2010

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We have developed a simple and convenient synthetic strategy for the preparation of tetrahydropyranyl, 4-methoxytetrahydropyranyl, and tetrahydrofuranyl ethers of 2Ј-deoxynucleosides, which are useful building blocks for nucleic acid chemistry. Enzymatic benzoylation provides an efficient alternative for protecting the 5Ј-hydroxy group of the parent nucleosides in a regioselective manner. Subsequently, tetra-

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The Protection of Hydroxyl Groups

Cited by 135 publications

References 0 publications

Volatile Organic Compounds from Arctic Bacteria of the Cytophaga‐Flavobacterium‐Bacteroides Group: A Retrobiosynthetic Approach in Chemotaxonomic Investigations

Volatile Organic Compounds from Arctic Bacteria of the Cytophaga‐Flavobacterium‐Bacteroides Group: A Retrobiosynthetic Approach in Chemotaxonomic Investigations

Tetrahydropyranyl protection and deprotection of alcohols using a niobium-based Brønsted acid catalyst

Chemoenzymatic Synthesis of 3′‐O‐Acetal‐Protected 2′‐Deoxynucleosides as Building Blocks for Nucleic Acid Chemistry

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