(4R)-3,4-dihydro-2H-chromen-4-ol

Conditions: temp:30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Argon was introduced into a 20 mL Schlenk-type reaction tube and bathed in an ice bath, then triethyl amine (3.6 mL, 26 mmol), formic acid (1.2 mL, 31 mmol), 4-chromanone (1.48 g, 10 mmol, substrate/catalyst ratio=500) and ruthenium complex RuCl[(R,R)-Tsdpen] (p-cymene) (12.7 mg, 0.02 mmol) were set therein, stirred at 30° C. for 24 hours. On its course, samples were collected after 3 hours for 1HNMR and HPLC analyses of the product. The conversion rate after 3 hours was 66%, and the optical purity was 99% ee. The reaction was allowed to further continue, and after 24 hours, (R)-4-chromanol was produced at 100% yield of and 99% ee optical purity. Argon was introduced into a 20 mL Schlenk-type reaction tube bathed in an ice bath On its course, samples were collected after 3 hours for 1HNMR and HPLC analyses of the product The conversion rate after 3 hours was after 24 hours

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 50-ml autoclave, 3.3 mg (0.005 mmol, S/C=1000) of RuCl(R,R)—O-HT-Tsdpen) was placed, and the autoclave was purged with nitrogen. Subsequently, 0.74 g (5.0 mmol) of 4-chromanone and 4.4 ml of methanol were added thereto, and the pressure was raised with hydrogen up to 3.0 MPa. Subsequently, the mixture was stirred for 18 hours at 60° C. The reaction liquid was subjected to a GC analysis, and as a result, (R)-4-chromanol was obtained at a conversion rate of 98.6% with an optical purity of 99.1% ee. the autoclave was purged with nitrogen The reaction liquid