1-(3,4-dihydro-2H-chromen-2-yl)-2-[[2-(3,4-dihydro-2H-chromen-2-yl)-2-hydroxyethyl]amino]ethanol

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

Procedure: To a stirred solution of 1 part of (A+A+)-α,α'-[iminobis(methylene)]bis[3,4-dihydro-2H-1-benzopyran-2-methanol] in 16 parts of 2-propanol were added dropwise 8 parts of 2-propanol saturated with hydrogen bromide. The product was filtered off and crystallized from 2-propanol. The product was filtered off and dried, yielding 0.8 parts of (A+A+)-α,α'-[iminobis(methylene)]bis[3,4-dihydro-2H-1-benzopyran-2-methanol]hydrobromide; mp. 236.5° C.; [α]589 =+114.53° (c=1% CH3OH) (compound 142). The product was filtered off crystallized from 2-propanol The product was filtered off dried

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

Procedure: A mixture of 3 parts of (A+A+)-α,α'-[[(phenylmethyl)imino]bis(methylene)]bis[3,4-dihydro-2H-1-benzopyran-2-methanol] and 120 parts of methanol was hydrogenated at normal pressure and at room temperature with 2 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was taken up in dichloromethane. The organic phase was washed with a 10% sodium hydroxide solution and with water, dried, filtered and evaporated. The residue was dried in vacuo at 80° C., yielding 1.2 parts (19%) of (A+A+)-α,α'-[iminobis(methylene)]bis[3,4-dihydro-2H-1-benzopyran-2-methanol]; mp. 130.8° C.; [α]589 =+121.50° (c=1% CH3OH) (compound 74). the catalyst was filtered off the filtrate was evaporated The organic phase was washed with a 10% sodium hydroxide solution and with water dried filtered evaporated The residue was dried in vacuo at 80° C.