Highly selective silver(I) oxide mediated monoprotection of symmetrical diols

Bouzide, Abderrahim; Sauvé, Gilles

doi:10.1016/s0040-4039(97)01328-2

Cited by 134 publications

(96 citation statements)

References 17 publications

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“…Now only a change of protecting groups was required to intercept intermediate 121. [39,40] Nucleophile additions to an aldehyde with quaternary acenter: When we observed the unusual behaviour of aldehyde 50 in the aldol addition, we decided to investigate this kind of substrates further. Thus, starting from aldehyde 123, easily accessible by oxidation of alcohol 41, a variety of allylation protocols were tested (Scheme 29, Table 3 [41] In the Brown or Roush allylation adduct 124 a was preferred, and the influence of the chiral ligand was of minor importance.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of (Z)‐Trisubstituted Olefins by Decarboxylative Grob‐Type Fragmentations: Epothilone D, Discodermolide, and Peloruside A

Prantz

Mulzer

2009

Chemistry A European J

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Methyl-branched (Z)-trisubstituted olefins are found in many polyketides with interesting biological activity, such as epothilone D (1), discodermolide (3), and peloruside A (2). Despite the employment of numerous different strategies, this motif has often been the weak point in total synthesis. Thus, we present a novel hydroxide- induced Grob-type fragmentation as an easy access to trisubstituted olefins. In our case, beta-mesyloxy delta-lactones with three stereogenic centers were chosen whose fragmentation underlies a high stereoelectronic control. Major challenges in the syntheses were the installation of quaternary stereocenters, achieved by enzymatic desymmetrization of meso-diesters and by aluminium-promoted stereoselective rearrangement of chiral epoxides, respectively. Different aldol strategies were developed for the formation of the fragmentation precursors. Additionally a short survey about nucleophilic additions to aldehydes with quaternary alpha-centers is presented.

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Section: Resultsmentioning

confidence: 99%

Synthesis of (Z)‐Trisubstituted Olefins by Decarboxylative Grob‐Type Fragmentations: Epothilone D, Discodermolide, and Peloruside A

Prantz

Mulzer

2009

Chemistry A European J

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“…Benzylation of 4, using potassium hydride 2 and benzyl bromide led to poor yields (~20%) of tri-protected 6. A significant improvement in the yield (70%) was obtained when the potassium hydride was replaced by silver oxide 3 . Lastly we were pleased to find that oxidative rearrangement 4 of benzoates 5 and 6 led smoothly to the new δ- …”

Section: Resultsmentioning

confidence: 99%

“…BF 3 .Et 2 O (0.012 ml, 0.013 g, 0.092 mmol) was added. The reaction was stirred at -20˚ for 3.5 hr and quenched with saturated NaHCO 3 solution (10 ml).…”

Section: 5-anhydro-4-o-benzoyl-6-o-t-butyldiphenylsilyl-23-deoxy-1mentioning

confidence: 99%

Diastereoselective conjugate additions of a D-glucose-derived δ-lactone

Ciampini¹,

Perlmutter²,

Watson³

2003

Arkivoc

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“…[1] In the past, many stoichiometric methods have been developed, such as reductive cleavage of acetals, [2] use of polymer resins, [3] thallium salts, [4] monosodium salts, [5] silver oxide, [6] dibutyltin oxide, [7] arylboronic acids, [8] and direct allylation of 1,2-diols through intramolecular dehydrohalo-A C H T U N G T R E N N U N G genation. [9] On the other hand, only a few catalytic reactions were reported with limited successful examples using tin dichloride, [10] palladium salts, [11] phase-transfer catalysts, [12] and crown ether.…”

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confidence: 99%