Boron trifluoride etherate → 5-Allyloxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

To a solution of 5-methoxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester, 3, (9.86 g, 38.0 mmol) and allyltrimethylsilane (13.0 g, 114 mmol) in CH2Cl2 (200 mL) at −78° C. is added dropwise boron trifluoride etherate (4.82 mL, 38.0 mmol). Once consumption of the starting material is complete, water is cautiously added to quench the reaction. The resulting solution is taken up in ethyl acetate (200 mL) washed with water (1×250 mL), brine (1×250 mL), and dried with Na2SO4. The organics are concentrated in vacuo. The resulting residue is purified over silica (hexanes/ethyl acetate 85:15) to afford 6.2 g (61% yield) of the desired product as a light yellow oil. 1H-NMR (300 MHz, CDCl3): δ 5.85–5.70 (m, 1H), 5.09–5.00 (m, 2H), 4.31–4.16 (m, 1H), 3.95–3.76 (br m, 1H), 3.71–3.69 (m, 3H), 2.72–2.57 (br m, 1H), 2.24–1.69 (m, 5H), 1.45–1.38 (m, 9H); MS (ESI): m/e=270.11 (M+H).

1. customOnce consumption of the starting material
2. additionwater is cautiously added
3. customto quench
4. customthe reaction
5. washwashed with water (1×250 mL), brine (1×250 mL)
6. dry with materialdried with Na2SO4
7. concentrationThe organics are concentrated in vacuo
8. customThe resulting residue is purified over silica (hexanes/ethyl acetate 85:15)

ORD record

ord-afc56605091948caa7acc09e3c57cb9c

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07041696B2