115346-74-2

Upstream product

• 491-07-6 (+/-)-menthone 
• 115346-89-9 5-phenyl-1,3-bis(trimethylsiloxy)pentane 
• 10458-14-7 (2R,5S)-menthone 
• 104-53-0 3-phenyl-propionaldehyde 
• 115404-97-2 5-phenyl-pentane-1,3-diol 
• 53376-62-8 ethyl 3-hydroxy-5-phenylpentanoate 

Downstream Products

• 115346-55-9 (-)-(3S)-5-phenylpentane-1,3-diol 

Relevant academic research and scientific papers

Stereoselective acetalization of 1,3-alkanediols controlled by intramolecular van der Waals attractive interactions and its application to an enantiodifferentiating transformation of σ-symmetric 1,3,5-pentanetriols

Acetalization reactions of racemic bis(trimethylsilyl) ethers (R1R2CHCH(OTMS)CH(R3)CH2OTMS) with racemic menthone, under thermodynamically controlled conditions, stereoselectively give spiroacetal 2 (in which the substituent R1R2CH- is attached to the carbon adjacent to the axial oxygen atom with respect to the menthane ring) in preference to the diastereomeric spiroacetal 3 (in which the substituent is attached to the carbon adjacent to the equatorial oxygen atom). Correlation between the stereoselectivities and the structures of the spiroacetals as well as the higher stereoselectivities observed in the related acetalization with 7,7,7-trimethylmenthone indicates that the preferential formation of spiroacetal 2 of a folded structure is a result of intramolecular attractive interactions between the menthane moiety and the substituent attached to the 1,3-dioxane ring. Molecular mechanics (MM2) calculations give satisfactory agreement with experiments and provide support for the operation of the van der Waals attractive interaction as the most important factor determining the stereoselectivities. The stereoselective acetalization with l-menthone is successfully applied to a novel enantiodifferentiating transformation of σ-symmetric 1,3,5-pentanetriols (HOCH2CHRCH(OH)CHRCH2OH; R = Me or H). The reaction provides an efficient and straightforward route to chiral menthonide derivatives 13a-c, which can be utilized as versatile chiral building blocks.

Stereoselective Acetalization of 1,3-Alkanediols by l-Menthone: Application to the Resolution of Racemic 1,3-Alkanediols and to the Determination of the Absolute Configuration of Enantiomeric 1,3-Alkanediols

A general and reliable method for the resolution of racemic 1,3-alkanediols, which involves their conversion into diastereomeric spiroacetals derived from l-menthone, is described.Thus, the reaction of the bis-O-trimethylsilyl derivatives of racemic 1,3-alkanediols with l-menthone in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate affords the diastereomeric spiroacetals 3 and 4.The two can be readily separated by silica gel column chromatography.Hydrolysis of each diastereomer under acidic conditions liberates the corresponding enantiomerically pure diol.An empirically derived correlation of configuration and 1H NMR chemical shifts for spiroacetals 3 and 4 has been developed which is rationalized based on long-range effects due to the magnetic anisotropy inherent to the menthane ring in a rigid spiroacetal conformation.The method described here should be widely applicable to the determination of the absolute configuration of various 1,3-alkanediols.

Enantioselective acetalization of racemic 1,3-alkanediols with l-methone under kinetically controlled conditions

Racemic 1,3-alkanediols (rac-1) undergo an enantioselective acetalization by treatment with l-methone enol trimethylsilyl ether (10) in the presence of trifluoromethanesulfonic acid (10 mol%) to give thermodynamically less stable spiroacetal 3 (derived fr

ENANTIODIFFERENTIATING TRANSFORMATION OF PROCHIRAL 1,3,5-PENTANETRIOLS CONTROLLED BY INTRAMOLECULAR VAN DER WAALS ATTRACTIONS

Acetalization of prochiral 1,3,5-pentanetriol derivatives (5) with l-menthone proceeded enatioselectively (3.0-4.6:1) to give spiroacetals (6) which can be utilized as versatile chiral building blocks.

RESOLUTION OF 1,3-ALKANEDIOLS VIA CHIRAL SPIROKETALS DERIVED FROM l-MENTHONE

Ketalization reaction of racemic 1,3-alkanediols with l-menthone gave a mixture of diastereomeric spiroketals that was easily separated by silica gel column chromatography and converted into enantiomerically pure diols by acid-catalyzed hydrolysis.