2-hydroxy-l-indanone

Figure 16.2-53. Chemoenzymatic synthesis of 2-hydroxy-l-indanone. The racemic syn and anti diols were prepared by chemical dihydroxylation of indane. Asymmetric induction was achieved by microbial oxidation (MO) of these diols.

Kato et al. described the stereoselective microbial synthesis of both enantiomers of 2-hydroxy-l-indanone, selecting cis- or trans-diol as the substrate (Fig. 16.2-53). Cis-... 

Table 16.2-16 shows the stereoselective oxidation of racemic cis-diol or frans-diol into optically active 2-hydroxy-l-indanone at a 2 mL scale with 50 mg dry cells per ml. 

Fig. 8.40 One-pot reactions sequence, including hydrogenation of prochiral diketone 1,2-indanedione (I) with chemoenzymatic dynamic kinetic resolution of the resulting rac-2-hydroxy-l-indanone by racemization of (S)-2-hydroxy-l-indanone into (ff)-2-hydroxy-l-indanone and acylation of the latter to (ff)-2-acetoxy-l-indanone. (From O. Langvik, T. Sandberg, J. Wdrnd, D.Yu. Murzin, R. Leino, One-pot synthesis of (R)-2-acetoxy-l-indanone from 1,2-indanedione combining metai cataiyzed hydrogenation and chemoenzymatic dynamic kinetic resoiution, dynamic kinetic resoiution, Catai. Sci. Technoi 5 (2015) 150—160. Copyright the Royai Society of Chemistry).

This simple, one-step ring expansion is the only available method for the preparation of 2-hydroxy-3-alkylisocarbostyrils in good yield from the corresponding 2-alkyl-l-indanones. Table I lists five new hydroxyisocarbostyrils prepared in this manner. 

Alkenyl-l-alkynylcyclopropane 33 underwent rhodium-catalyzed tandem Pauson-Khand reaction/spiropentane carbonylation to give 6-hydroxy-l-indanone 34 (Scheme 2.30) [46]. 

An alternative approach to the synthesis of isocoumarins which probably proceeds through the intermediacy of 2-carboxybenzyl ketones is based on the oxidative cleavage of indan-1-ones (76JCS(P1)1438). Although ozonolysis of the silyl enol ether (505) leads to the 2-hydroxy-2-methylindan-l-one (506), periodate oxidation of which gives the isocoumarin, a more convenient and direct route involves ozonolysis of the enol trifluoroacetate (Scheme 182). This synthesis is especially attractive for the preparation of isotopically labelled isocoumarins, since the precursors of the indanones, arylpropanoic acids or acrylophenones, are readily available bearing labels at specific sites. 

The oxidation of indene with peroxyformic acid gives a 69-81% yield of 2-indanone after hydrolysis of the intermediate, l-formoxy-2-hydroxy-indane (equation 91) [246],... 

Rhodococcus sp. 124 was isolated fi-om a toluene-contaminated aquifer and was found to oxidize indene to 1,2-indandiol and several other products. The undesired products 1-indenol and 1-indanone were formed directly from indene while racemic l-keto-2-hydroxy-indan was formed from the indandiols. Based on product formation profiles and induction experiments, 124 was hypothesized... 

The rearrangement of (a-hydroxyalkyl)phosphonate into phosphate ester is not universal (l-hydroxy-2-nitroalkyl)phosphonic esters do not rearrange under the influence of heat whether aided, or not, by added base and the reaction between (Me0)2P(0)H and MeCOCH=CHPh at 130-160 °C yields the 1,2-adduct (105 R = Me) which is stable to base (MeO or EtjN). On the other hand, 105 (R = H) partially decomposes in the presence of MeO and the products include the phosphate 106 together with methyl cinnamate and cinnamyl alcohol, as might be expected from the action of base on cinnamaldehyde Other compounds which undergo base-catalysed rearrangements include 107, the indanones 108 (R = H or the hydroxy phosphinic esters 109 (X = O or S, R =... 

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