Diastereo- and enantioselective synthesis of anti-1,3-mercapto alcohols from α,β-unsaturated ketones via tandem Michael addition–MPV reduction

Evaluation of ethyl 2-carbomethoxyethenesulfinates as 2-hydroxymethyl enethiol equivalents in the Diels–Alder reaction

“…Chiral compounds possessing mercapto and hydroxy groups in a constrained proximity or derivatives of such compounds are valuable as chiral auxiliaries in organic synthesis. [54][55][56][57][58] Under chiral cycloaddition conditions, the dienophiles would serve as 'chiral' enethiol equivalents.…”

Photo‐biocatalytic One‐Pot Cascades for the Enantioselective Synthesis of 1,3‐Mercaptoalkanol Volatile Sulfur Compounds

“…The conversion of 5a into alcohol 6a and the ee value of the product were determined by HPLC (Table 1, entry 1). Although KRED 290, 296, and 363 led to alcohol 6ain alow amount with poor enantioselectivity (15,12, and 8% ee,r espectively), the S enantiomer was formed as the only product. Although KRED 290, 296, and 363 led to alcohol 6ain alow amount with poor enantioselectivity (15,12, and 8% ee,r espectively), the S enantiomer was formed as the only product.…”

“…Strikingly,aremarkable variability in both conversion and selectivity was observed. Although KRED 290, 296, and 363 led to alcohol 6ain alow amount with poor enantioselectivity (15,12, and 8% ee,r espectively), the S enantiomer was formed as the only product. In contrast, biocatalysts KRED311 and 349 fully converted 5a into 6a (99 %) with excellent enantioselectivity (99 and 97 % ee,r espectively).…”

“…[4a, 9, 11] 1,3-Mercaptoalkanols can be obtained in enantiomerically pure form through preparative GC resolution of the corresponding racemic mixtures [9] or through the chemical reduction of ketones using chiral auxiliaries [12] or metal catalysts. [4a, 9, 11] 1,3-Mercaptoalkanols can be obtained in enantiomerically pure form through preparative GC resolution of the corresponding racemic mixtures [9] or through the chemical reduction of ketones using chiral auxiliaries [12] or metal catalysts.…”

“…From achemical point of view,20-30 %ofVSCs are 1,3mercaptoalkanols,m aking them the most important sulfur compounds with aroma activity. [4a, 9,11] 1,3-Mercaptoalkanols can be obtained in enantiomerically pure form through preparative GC resolution of the corresponding racemic mixtures [9] or through the chemical reduction of ketones using chiral auxiliaries [12] or metal catalysts. [13] However,t hese approaches suffer from limitations in terms of sustainability with respect to atom economy,the use of non-green solvents, and catalyst recyclability.G reener biocatalytic approaches have been developed on the basis of lipase-mediated kinetic enzymatic resolution [14] or the bakersy east mediated reduction of carbonyl precursors [15] (Figure 1).…”