Tert-butyl 5-[2-(dichloromethyl)-4(rs),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(rs)-methylvalerate → Tert-butyl 5-[2-(1(rs)-chloropropyl)-4(rs),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(rs)-methylvalerate

HRID 362142Notes

Reaction equation

Cl[CH:2]([Cl:23])[B:3]1[O:7][C:6]([CH2:9][CH2:10][CH:11]([CH3:20])[CH2:12][C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])([CH3:8])[C:5]([CH3:22])([CH3:21])[O:4]1.[CH2:24]([Mg]Br)[CH3:25]>O1CCCC1.C(OCC)(=O)C>[Cl:23][CH:2]([B:3]1[O:7][C:6]([CH2:9][CH2:10][CH:11]([CH3:20])[CH2:12][C:13]([O:15][C:16]([CH3:17])([CH3:18])[CH3:19])=[O:14])([CH3:8])[C:5]([CH3:21])([CH3:22])[O:4]1)[CH2:24][CH3:25]

Participants

Conditions

Temperature: -78 °C

Procedure

0.86 g (2.3 mmol) of tert-butyl 5-[2-(dichloromethyl)-4(RS), 5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(RS)-methylvalerate was dissolved in 5 ml of tetrahydrofuran and the solution was cooled to -78° C. under a nitrogen atmosphere. 2.6 ml (2.6 mmol) of 1 M ethylmagnesium bromide in tetrahydrofuran were added dropwise, the resulting solution wasstirred for 16 hours while slowly warming to room temperature and then diluted with ethyl acetate and extracted with 2M hydrochloric acid and brine. The organic phase was dried over sodium sulphate and then evporatedunder a vacuum to give 0.83 g of tert-butyl 5-[2-(1(RS)-chloropropyl)-4(RS),5,5-trimethyl-1,3,2-dioxaborolan-4-yl]-3(RS)-methylvalerate as an oil which was used in the next step without purification.

Workup

temperaturewhile slowly warming to room temperature
extractionextracted with 2M hydrochloric acid and brine
dry with materialThe organic phase was dried over sodium sulphate

Sources & evidence

ORD record: ord-ba523794496146a7b2207d7a97ddb400
Source dataset: uspto-grants-1999_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05866684

Reaction notes

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