(S)-N-(9-Phenylfluoren-9-yl)alanine and (S)-Dimethyl n-(9-phenylfluoren-9-yl)aspartate could be produced through the following synthesis routes.

A. (S)-N-(9-Phenylfluoren-9-yl)alanine (CAS no ). A 1-L, flame-dried, three-necked Morton flask equipped with an overhead stirrer, rubber septum, and reflux condenser (equipped with a rubber septum) under a nitrogen atmosphere is charged with L-alanine (13.5 g, 150 mmol), chloroform (375 mL), acetonitrile (75 mL), and chlorotrimethylsilane (19.04 mL, 150 mmol). The rubber septum in the neck of the Morton flask is replaced with a glass stopper, and the mixture is heated at reflux for 2 hr with vigorous stirring under an inert atmosphere. The mixture is cooled to room temperature under a stream of nitrogen, triethylamine (46.0 mL, 330 mmol) is added via syringe at a rate sufficient to maintain a gentle reflux, and the mixture is stirred for 15 min after which Pb(NO₃)₂ (33.1 g, 100 mmol) is added. The glass stopper is replaced with a rubber septum, and a solution of 9-bromo-9-phenylfluorene (57.8 g, 180 mmol) in chloroform (180 mL) is added via a cannula with a positive nitrogen pressure. The reflux condenser is replaced with a glass stopper, and an 18-gauge syringe needle equipped with an argon-filled balloon is inserted in the rubber septum. The heterogeneous, off-white mixture is stirred vigorously under this inert atmosphere for 48 hr. After about 20 hr, the reaction mixture becomes orange and darkens over time. (15.2 mL, 375 mmol) is then added, and the mixture is stirred an additional 30 min.

The mixture is filtered using a sintered glass filter, the filter cake is washed by stirring with chloroform (3 × 50 mL), and the dark orange filtrate is evaporated to a residue that is partitioned between ether (750 mL) and aqueous 5% citric acid (750 mL). The layers are separated, and the aqueous layer is extracted with ether (4 × 250 mL). The combined organic solutions are extracted with 1 M sodium hydroxide (300 mL). The aqueous solution is washed with 300 mL of ether, cooled to 0°C with stirring using a magnetic stir bar, and the pH is adjusted to 7 by the dropwise addition of glacial acetic acid (approximately 17 mL). The mixture now containing an off-white precipitate is extracted with 25% 2-propanol in chloroform (3 × 300 mL). The combined organic solutions are washed with 150 mL of saturated sodium chloride solution, dried (Na₂SO₄), filtered, and evaporated to a light yellow foam that is dried under reduced pressure to give 39.2 g (80% yield) of (S)-N-(9-phenylfluoren-9-yl)alanine.

B. (S)-Dimethyl N-(9-phenylfluoren-9-yl)aspartate (CAS no ). A 1-L, flame-dried, three-necked Morton flask equipped with an overhead stirrer and two rubber septa under a nitrogen atmosphere is charged with Pb(NO₃)₂ (28.2 g, 85.0 mmol), K₃PO₄ (44.6 g, 210 mmol), and acetonitrile (250 mL). (S)-Dimethyl aspartate hydrochloride (19.8 g, 100 mmol) is added, followed by 9-bromo-9-phenylfluorene (40.15 g, 125 mmol). The off-white, heterogeneous mixture is stirred vigorously for 22 hr, and to the mixture is added methanol (40.5 mL, 1.00 mol); the mixture is stirred an additional 30 min and filtered through approximately 20 g of diatomaceous earth ("Celite") on a sintered glass funnel. The filter cake is washed by stirring with portions of chloroform until no UV chromophore can be detected in the filtrate. Silica (60 g) is added to the combined organic solutions, and the solvent is removed (rotary evaporator), leaving a dry powder. This powder is added to a column of silica (800 g) and the column is eluted with 10% ethyl acetate in hexanes to give 9-methoxy-9-phenylfluorene (5.30 g, 19.5 mmol) and then 9-phenyl-9-fluorenol (2.00 g, 7.7 mmol). A 1/1 mixture of 9-phenyl-9-fluorenol and (S)-Dimethyl N-(9-phenylfluoren-9-yl)aspartate is eluted next (2.13 g). After all the 9-phenyl-9-fluorenol has been eluted, the eluting solvent is changed to 25% ethyl acetate in hexanes. The combined solutions of pure (S)-Dimethyl N-(9-phenylfluoren-9-yl)aspartate are evaporated (rotary evaporator), yielding (S)-dimethyl N-(9-phenylfluoren-9-yl)aspartate as a light yellow solid (36.1 g, 90 mmol, 90% yield) after drying for 1 day at 0.1 mm. The 2.13-g mixture of (S)-Dimethyl N-(9-phenylfluoren-9-yl)aspartate and 9-phenyl-9-fluorenol can be rechromatographed (100 g of silica, 10–25% ethyl acetate in hexane) to give an additional 0.8 g (3.1 mmol) of 9-phenyl-9-fluorenol (for a total of 2.80 g, 10.8 mmol) and 1.3 g (3.2 mmol, 3.2% yield) of (S)-Dimethyl N-(9-phenylfluoren-9-yl)aspartate, for a total of 37.4 g (93% yield) of (S)-Dimethyl N-(9-phenylfluoren-9-yl)aspartate.