88083-79-8

Upstream product

• 88083-97-0 Triethyl-((2S,6S)-6-methyl-2-phenyl-3,6-dihydro-2H-pyran-4-yloxy)-silane 
• 63446-76-4 1-methyl-1,3-bis(trimethylsilyloxy)buta-1,3-diene 
• 100-52-7 benzaldehyde 
• 69122-26-5 (E)-4-methoxy-2-trimethylsiloxypenta-1,3-diene 
• 123-54-6 acetylacetone 
• 79144-14-2 6-hydroxy-6-phenyl-hexane-2,4-dione 
• 88083-96-9 (3E)-2-triethylsilyloxy-1,3-pentadiene 
• 3102-33-8 trans-3-penten-2-one 
• 10556-93-1 4-methoxypent-3-en-2-one 
• 879497-21-9 1-hydroxy-5-methoxy-1-phenylhex-4-en-3-one 
• 651738-86-2 (E)-1-hydroxy-1-phenylhex-4-en-3-one 
• 94110-22-2 cis-2-methyl-6-phenyl-4-((triethylsilyl)oxy)-5,6-dihydro-2H-pyran 

Relevant academic research and scientific papers

Cobalt-catalyzed 1,4-hydrovinylation of allylsilane and allylboronic esters for the synthesis of hydroxy-functionalized 1,4-dienes

(Figure presented) The cobalt(I)-catalyzed 1,4-hydrovinylation reaction of allyl trimethylsilane and allyl pinacol boronic ester with symmetrical and unsymmetrical 1,3-dienes generates building blocks for the in situ allylboration or the Lewis acid induced allylation reaction utilizing the corresponding allyl silane derivatives. The products of these three-component reactions are hydroxy-functionalized 1,4-dienes which can be used for the synthesis of pyranones. An alternate reaction sequence for the synthesis of the hydroxy-functionalized 1,4-dienes by performing the allylation first followed by the cobalt-catalyzed 1,4-hydrovinylation is also possible. Accordingly, polyfunctionalized complex structures can be generated by both approaches in a convergent fashion.

Cyclization vs. elimination reactions of 5-Aryl-5-hydroxy 1,3-diones: One-pot synthesis of 2-Aryl-2,3-dihydro-4H-pyran-4-ones

2-Aryl-2,3-dihydro-4H-pyran-4-ones were prepared in one step by cyclocondensation of 1,3-diketone dianions with aldehydes. The use of HCl (10%) for the aqueous workup proved to be very important to avoid elimination reactions of the 5-aryl-5-hydroxy 1,3-d

One-pot synthesis of 6-aryl-2,3-dihydro-4H-pyran-4-ones by cyclocondensation of 1,3-diketone dianions with aldehydes

6-Aryl-2,3-dihydro-4H-pyran-4-ones were prepared in one step by cyclocondensation of 1,3-diketone dianions with aldehydes. The use of hydrochloric acid (10%) for the aqueous work-up proved to be very important.

A convenient and versatile approach to 2,3-dihydro-4H-pyran-4-ones via tandem aldol reaction-conjugate addition

Aldol reaction of enones 1a-c with aldehydes followed by intramolecular conjugate addition proceeded smoothly to afford corresponding 2,3-dihydro-4H-pyran-4-ones in high yields under mild conditions.

Highly enantioselective synthesis of 2,6-disubstituted and 2,2,6-trisubstituted dihydropyrones: A one-step synthesis of (R)-(+)-hepialone and its analogues

An efficient enantioselective approach to chiral dihydropyrones has been developed by the hetero-Diels-Alder (HDA) reactions of (E)-4-methoxy-2- trimethylsiloxy-penta-1,3-diene (diene 1) with aldehydes and pyruvates. It has been found that the readily accessible (R)-BINOL-Ti(OiPr)4 (1.1:1) complex was a very effective catalyst for this reaction. Aromatic, heteroaromatic, conjugated, and aliphatic aldehydes afforded the corresponding products in moderate to high isolated yields (up to 99%) with excellent enantioselectivities (up to 99% ee). The first example of highly enantioselective synthesis of 2,2,6-trisubstituted dihydropyrones by the catalytic reaction of diene 1 with pyruvates was reported. The isolated intermediates indicated that this asymmetric HDA reaction proceeded in a Mukaiyama aldol pathway. On the basis of the absolute configurations of the products, a possible mechanism was proposed. Moreover, the catalytic system could be used to synthesize a series of enantioenriched β-hydroxyketones 4. Finally, this methodology was successfully applied for the one-step synthesis of the important natural product (R)-(+)-Hepialone with 88% isolated yield and 94% enantioselectivity.

Oxidative Cyclization of β-Hydroxyenones with Palladium(II): A Novel Entry to 2,3-Dihydro-4H-pyran-4-ones

(Equation presented) A palladium(II)-mediated oxidative cyclization was found to be effective for the preparation of structurally diverse 2,3-dihydro-4H-pyran-4-ones from the corresponding β-hydroxyenones. Attractive features of this transformation includ

Experiments directed towards the synthesis of anthracyclinones. XXXIV hetero-diels-alder reactions using chiral boron and titanium reagents

Reactions between benzaldehyde or o-anisaldehyde and a series of silyloxy dienes catalysed by the chiral acyloxyborane (CAB) complex (4) give high yields of enantioselective products from a Mukaiyama aldol rather than a hetero-Diels-Alder reaction. Attempts to effect a similar catalytic reaction with anthraquinone aldehydes were unsuccessful but use of 2 equiv. of the CAB complex (1) followed by cyclization promotes a formal heteroDiels-Alder reaction between the aldehyde (7) and the diene (12) to give the dihydropyrone (24) in 45% yield and with a 79% e.e. in favour of the 2′R enantiomer. Hetero-Diels-Alder reactions between the aldehyde (7) and the diene (12) using the chiral titanium complexes Ti[(R)-BINOL]Cl2, Ti[(R,R)-TADDOL]Cl2 and Ti[(R)-BINOL]2 have been investigated. The first two complexes promote the reaction at -30 and -78° respectively but with low induced enantioselectivities.

Total Synthesis of Vineomycinone B2 Methyl Ester

Two homo-Diels-Alder reactions and a hetero-Diels-Alder reaction, each using siloxydienes, were used in a total synthesis of the title compound.

Expeditious Routes to Multiply Functionalized Pyrans

The scope of the Lewis acid catalyzed cyclocondensation reaction of activated dienes and aldehydes has been investigated.With a 3-(trialkylsilyl)oxy group in the basic diene, the reaction has been shown to be feasible with 1,1-dimethoxy, 1-(silyloxy)-1-al