Homoserine

Off-White Crystalline Solid

Homoserine is an alpha-amino acid that is glycine substituted at the alpha-position by a 2-hydroxyethyl group. It has a role as a metabolite. It is a conjugate acid of a homoserinate.

A solution of homoserine (5.00 g, 42.0 mmoles) in 50percent aqueous acetone (50 mL), was treated with triethylamine (8.8 mL, 6.39 g, 63.0 mmoles) and BOC anhydride (10.1 g, 46.2 mmoles), and stirred overnight at room temperature. Removal of the solvent gave the salt (13.5 g, 100percent). 1Hmr (D2O, delta): 4.02 (1H, m, CHalpha), 3.64 (2H, m, CH2gamma), 3.18 (2H, q, 7.3 Hz, CH2CH3) 1.98 (1H, m, CHbeta), 1.82 (1H, m, CHbeta), 1.41 (9H, s, C(CH3)3), 1.26 (3H, t, 7.3 Hz, CH3). 13Cmr (D2O, delta): 181.68, 160.33, 83.76 61.09, 55.48, 49.30, 36.57, 30.28, 10.85. IR (CH2Cl2): 3413, 1709, 1693 cm-1. Mass spectrum (CI, m/z): 164 (M+1-BOC).A solution of DL-homoserine (0.31 g, 2.6 mmoles) in 2.4 M hydrobromic acid (5 mL, 12 mmoles, 4.6 eq) was refluxed for 3 h and then stirred overnight. Removal of the solvent afforded a white solid, which was dissolved in ethanol and cooled to give the product as a solid which was collected by filtration and washed with cold ethanol to give 0.384 g (81percent) of the product (A), m.p. 117-119° C. Calcd. for C4H8NO2Br: C, 26.40; H, 4.44; N, 7.70. Found: C, 26.35; H, 4.25; N, 7.51.(a) 11.9 g of DL-homoserine was dissolved in 200 ml of water, and 10 g of Na2CO3 and 150 ml of dioxane were added thereto. 50 ml of a dioxane solution containing 27.5 g of di-t-butyl dicarbonate was added dropwise thereto over an hour. Thereafter, a reaction was effected at room temperature for 2 hours. After completion of the reaction, the dioxane was removed under reduced pressure, the residue was washed with ethyl acetate, and, after adjusting the pH to 2 with 5 N hydrochloric acid with ice cooling, extracted twice with 400 ml of ethyl acetate. The ethyl acetate layer was washed with saturated saline, dried on magensium sulfate, and concentrated to dryness to obtain 18.5 g of N-t-butoxycarbonyl DL-homoserine.Step 1: Preparation of 2-(tert-butoxycarbonylamino)-4-hydroxy-butanoic acid A mixture of DL-homoserine (2.0 g, 16.79 mmol, DIEA (4.3 g, 33.58 mmol) and Boc2O (4.0 g, 18.47 mmol) in acetone (50 mL) and H2O (50 mL) was stirred at 30 oC for 12 hrs. The resulting reaction mixture was concentrated in vacuo to give crude 2-(tert- butoxycarbonylamino)-4-hydroxy-butanoic acid (4.0 g) as yellow oil which was used directly in the next step without further purification.To a solution of DL-homoserine(A7, 12.12 g, 101.89 mmol) in 1N NaOH(111 mL) and EtOH(97 mL) was added a solution of Boc anhydride(24.43 g, 112 mmol) in THF(97 mL) over 15 minutes. The reaction mixture was stirred at room temperature for 16 h. The mixture was then washed with ether(3x200 mL), acidified with 1N HC1 to pH 2 and extracted with ethyl acetate(6x250 mL). The combined organic extracts were washed with brine(250 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. To afford 5.9 g of A8 as a colourless liquid. MS(ESI) m/z= 218.9[M+H]+.

Molecular Weight:119.12
XLogP3:-4.4
Hydrogen Bond Donor Count:3
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:3
Exact Mass:119.058243149
Monoisotopic Mass:119.058243149
Topological Polar Surface Area:83.6
Heavy Atom Count:8
Complexity:83.4
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes